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Sample records for global n-acetyl aspartate

  1. N-acetyl aspartate in autism spectrum disorders: Regional effects and relationship to FMRI activation

    PubMed Central

    Kleinhans, Natalia M.; Schweinsburg, Brian C.; Cohen, David N.; Müller, Ralph-Axel; Courchesne, Eric

    2009-01-01

    Rapid progress in our understanding of macrostructural abnormalities in autism spectrum disorders (ASD) has occurred in recent years. However, the relationship between the integrity of neural tissue and neural function has not been previously investigated. Single-voxel proton magnetic resonance spectroscopy and functional magnetic resonance imaging of an executive functioning task was obtained in 13 high functioning adolescents and adults with ASD and 13 age-matched controls. The ASD group showed significant reductions in N-acetyl aspartate (NAA) in all brain regions combined and a specific reduction in left frontal cortex compared to controls. Regression analyses revealed a significant group interaction effect between frontal and cerebellar NAA. In addition, a significant positive semi-partial correlation between left frontal lobe NAA and frontal lobe functional activation was found in the ASD group. These findings suggest that widespread neuronal dysfunction is present in high functioning individuals with ASD. Hypothesized developmental links between frontal and cerebellar vermis neural abnormalities were supported, in that impaired neuronal functioning in the vermis was associated with impaired neuronal functioning in the frontal lobes in the ASD group. Furthermore, this study provided the first direct evidence of the relationship between abnormal functional activation in prefrontal cortex and neuronal dysfunction in ASD. PMID:17612510

  2. Hippocampus Glutamate and N-Acetyl Aspartate Markers of Excitotoxic Neuronal Compromise in Posttraumatic Stress Disorder.

    PubMed

    Rosso, Isabelle M; Crowley, David J; Silveri, Marisa M; Rauch, Scott L; Jensen, J Eric

    2017-03-08

    Hippocampus atrophy is implicated in posttraumatic stress disorder (PTSD), and may partly reflect stress-induced glutamate excitotoxicity that culminates in neuron injury and manifests as re-experiencing symptoms and other memory abnormalities. This study used high-field proton magnetic resonance spectroscopy (MRS) to determine whether PTSD is associated with lower hippocampus levels of the neuron marker N-acetyl aspartate (NAA), along with higher levels of glutamate (Glu) and Glu/NAA. We also predicted that metabolite levels would correlate with re-experiencing symptoms and lifetime trauma load. Twenty-four adult PTSD patients and 23 trauma-exposed normal controls (TENC) underwent 4T MRS of the left and right hippocampus. Participants received psychiatric interviews, and completed the Traumatic Life Events Questionnaire to define lifetime trauma load. Relative to TENC participants, PTSD patients exhibited significantly lower NAA in right and left hippocampi, and significantly higher Glu and Glu/NAA in the right hippocampus. Re-experiencing symptoms were negatively correlated with left and right NAA, and positively correlated with right Glu and right Glu/NAA. Trauma load was positively correlated with right Glu/NAA in PTSD patients. When re-experiencing symptoms and trauma load were examined together in relation to right Glu/NAA, only re-experiencing symptoms remained a significant correlate. This represents the first report that PTSD is associated with MRS markers of hippocampus Glu excess, together with indices of compromised neuron integrity. Their robust associations with re-experiencing symptoms affirm that MRS indices of hippocampus neuron integrity and glutamate metabolism may reflect biomarkers of clinically significant disease variation in PTSD.Neuropsychopharmacology advance online publication, 8 March 2017; doi:10.1038/npp.2017.32.

  3. Serum levels of N-acetyl-aspartate in migraine and tension-type headache.

    PubMed

    de Tommaso, Marina; Ceci, Edmondo; Pica, Carmela; Trojano, Maria; Delussi, Marianna; Franco, Giovanni; Livrea, Paolo; Ruggieri, Maddalena

    2012-07-01

    Serum levels of N-acetyl-aspartate (NAA) may be considered a useful marker of neuronal functioning. We aimed to measure serum NAA in cohorts of migraine and tension-type headache patients versus controls, performing correlations with main clinical features. A total of 147 migraine patients (including migraine without aura, with aura and chronic migraine), 65 tension-type headache (including chronic and frequent episodic tension-type headache) and 34 sex- and age-matched controls were selected. Serum was stored at -80 °C. Quantification of NAA was achieved by the standard addition approach and analysis was performed with liquid-chromatography-mass-spectrometry (LC/MS) technique. The NAA levels were significantly decreased in migraine group (0.065 ± 0.019 mol/L), compared with both tension-type headache patients (0.078 ± 0.016 mol/L) and controls (0.085 ± 0.013 mol/L). Control subjects were significantly different from migraine with and without aura and chronic migraine, who differed significantly from episodic and chronic tension-type headache. Migraine with aura patients showed lower NAA levels when compared to all the other headache subtypes, including migraine without aura and chronic migraine. In the migraine group, no significant correlation was found between NAA serum levels, and headache frequency, allodynia and interval from the last and the next attack. The low NAA in the serum may be a sign of neuronal dysfunction predisposing to migraine, probably based on reduced mitochondria function.

  4. Associations between diffusion and perfusion parameters, N-acetyl aspartate, and lactate in acute ischemic stroke.

    PubMed

    Cvoro, Vera; Wardlaw, Joanna M; Marshall, Ian; Armitage, Paul A; Rivers, Carly S; Bastin, Mark E; Carpenter, Trevor K; Wartolowska, Karolina; Farrall, Andrew J; Dennis, Martin S

    2009-03-01

    In acute ischemic stroke, the amount of neuronal damage in hyperintense areas on MR diffusion imaging (DWI) is unclear. We used spectroscopic imaging to measure N-acetyl aspartate (NAA, a marker of normal neurons) and lactate (a marker of ischemia) to compare with diffusion and perfusion values in the diffusion lesion in acute ischemic stroke. We recruited patients with acute ischemic stroke prospectively and performed MR diffusion weighted (DWI), perfusion, and spectroscopic imaging. We coregistered the images, outlined the visible diffusion lesion, and extracted metabolite, perfusion, and apparent diffusion coefficient (ADC) values from the diffusion lesion. 42 patients were imaged, from 1.5 to 24 hours after stroke. In the DWI lesion, although NAA was reduced, there was no correlation between NAA and ADC or perfusion values. However, raised lactate correlated with reduced ADC (Spearman rho=0.32, P=0.04) and prolonged mean transit time (MTT, rho=0.31, P=0.04). Increasing DWI lesion size was associated with lower NAA and higher lactate (rho=-0.44, P=0.003; rho=0.49, P=0.001 respectively); NAA fell with increasing times to imaging (rho=-0.3, P=0.03), but lactate did not change. Although larger confirmatory studies are needed, the correlation of ADC and MTT with lactate but not NAA suggests that ADC and MTT are better markers of the presence of ischemia than of cumulative neuronal loss. Further studies should define more precisely the rate of neuronal loss and relationship to diffusion and perfusion parameters with respect to the depth and duration of ischemia.

  5. Phospho-N-Acetyl-Muramyl-Pentapeptide Translocase from Escherichia coli: Catalytic Role of Conserved Aspartic Acid Residues

    PubMed Central

    Lloyd, Adrian J.; Brandish, Philip E.; Gilbey, Andrea M.; Bugg, Timothy D. H.

    2004-01-01

    Phospho-N-acetyl-muramyl-pentapeptide translocase (translocase 1) catalyzes the first of a sequence of lipid-linked steps that ultimately assemble the peptidoglycan layer of the bacterial cell wall. This essential enzyme is the target of several natural product antibiotics and has recently been the focus of antimicrobial drug discovery programs. The catalytic mechanism of translocase 1 is believed to proceed via a covalent intermediate formed between phospho-N-acetyl-muramyl-pentapeptide and a nucleophilic amino acid residue. Amino acid sequence alignments of the translocase 1 family and members of the related transmembrane phosphosugar transferase superfamily revealed only three conserved residues that possess nucleophilic side chains: the aspartic acid residues D115, D116, and D267. Here we report the expression and partial purification of Escherichia coli translocase 1 as a C-terminal hexahistidine (C-His6) fusion protein. Three enzymes with the site-directed mutations D115N, D116N, and D267N were constructed, expressed, and purified as C-His6 fusions. Enzymatic analysis established that all three mutations eliminated translocase 1 activity, and this finding verified the essential role of these residues. By analogy with the structural environment of the double aspartate motif found in prenyl transferases, we propose a model whereby D115 and D116 chelate a magnesium ion that coordinates with the pyrophosphate bridge of the UDP-N-acetyl-muramyl-pentapeptide substrate and in which D267 therefore fulfills the role of the translocase 1 active-site nucleophile. PMID:14996806

  6. Suppressing N-Acetyl-l-Aspartate Synthesis Prevents Loss of Neurons in a Murine Model of Canavan Leukodystrophy.

    PubMed

    Sohn, Jiho; Bannerman, Peter; Guo, Fuzheng; Burns, Travis; Miers, Laird; Croteau, Christopher; Singhal, Naveen K; McDonough, Jennifer A; Pleasure, David

    2017-01-11

    Canavan disease is a leukodystrophy caused by aspartoacylase (ASPA) deficiency. The lack of functional ASPA, an enzyme enriched in oligodendroglia that cleaves N-acetyl-l-aspartate (NAA) to acetate and l-aspartic acid, elevates brain NAA and causes "spongiform" vacuolation of superficial brain white matter and neighboring gray matter. In children with Canavan disease, neuroimaging shows early-onset dysmyelination and progressive brain atrophy. Neuron loss has been documented at autopsy in some cases. Prior studies have shown that mice homozygous for the Aspa nonsense mutation Nur7 also develop brain vacuolation. We now report that numbers of cerebral cortical and cerebellar neurons are decreased and that cerebral cortex progressively thins in Aspa(Nur7/Nur7) mice. This neuronal pathology is prevented by constitutive disruption of Nat8l, which encodes the neuronal NAA-synthetic enzyme N-acetyltransferase-8-like.

  7. Right Dorsolateral Frontal Lobe N-Acetyl Aspartate and Myoinositol Concentration Estimation in Type 2 Diabetes with Magnetic Resonance Spectroscopy.

    PubMed

    Nagothu, Rajani Santhakumari; Reddy, Yogananda Indla; Rajagopalan, Archana; Varma, Ravi

    2015-07-01

    Chronic hyperglycaemia in type 2 diabetes, effects the central nervous system by altering the concentrations of brain metabolites like N-acetyl aspartate (NAA) and myoinositol (mI), which are indicators of neuronal integrity and glial cell damage respectively. Dorsolateral frontal lobe is associated with aspects of cognition especially right frontal lobe is involved in episodic memory retrieval, ninety percent of the diabetic cases are type 2 in nature globally and yoga is very effective in stabilizing the brain metabolites by bringing the blood glucose levels to near or within the physiological range in type 2 diabetes. The aim of the study was to observe the effects of yogasana and pranayama on glycosilated haemoglobin (HbA1c) levels and right dorsolateral frontal cortical NAA and mI concentration in type 2 diabetic subjects. It's a case control study. Sixty eight type 2 diabetic subjects of both the sex, aged between 35-65 years are included in the study, subjects are divided in to test and control group 34 each. Test group subjects did the yogasana and pranayama for a period of 6 months, 6 days in a week, 45-60 minutes daily under the supervision of a qualified yoga teacher. Control group subjects are not on any specific exercise regimen. Both the group subjects are taking oral hypoglycaemic agents. HbA1c levels are measured using the Bio-Rad D-10™ haemoglobin A1c program and Magnetic Resonance Spectroscopy (MRS) is used in assessing the metabolite concentrations. Analysis of data was done by using unpaired t-test. P-value for HbA1c level is <0.001, which is highly significant statistically. P-value for NAA was < 0.02 and for myoinositol was < 0.01, which are statistically significant. HbA1c levels in control and test group subjects are 7.7 ± 1.84 and 6.02 ± 0.46 respectively. NAA concentrations in the right dorsolateral frontal lobe of control and test group are 1.44 ± 0.15 and 1.54 ± 0.19 respectively. The mI concentrations in the right dorsolateral

  8. The relationship between Gulf war illness, brain N-acetyl aspartate and post-traumatic stress disorder

    PubMed Central

    Weiner, Michael W.; Meyerhoff, Dieter J.; Neylan, Thomas C.; Hlavin, Jennifer; Ramage, Erin R.; McCoy, Daniel; Studholme, Colin; Cardenas, Valerie; Marmar, Charles; Truran, Diana; Chu, Philip W.; Kornak, John; Furlong, Clement E.; McCarthy, Charles

    2012-01-01

    A previous study (1) suggested that individuals with Gulf War Illness (GWI) had reduced quantities of the neuronal marker N-acetyl aspartate (NAA) in the basal ganglia and pons. This study aimed to determine whether NAA is reduced in these regions and to investigate correlations with other possible causes of GWI, such as psychological response to stress in a large cohort of Gulf war veterans. Individuals underwent tests to determine their physical and psychological health and to identify veterans with (n=81) and without (n=97) GWI. When concentrations of NAA and ratios of NAA to creatine- and choline-containing metabolites were measured in the basal ganglia and pons, no significant differences were found between veterans with or without GWI, suggesting that GWI is not associated with reduced NAA in these regions. Veterans with GWI had significantly higher rates of Post Traumatic Stress Disorder (PTSD), supporting the idea that GWI symptoms are stress-related. PMID:21882779

  9. Lower "N"-Acetyl-Aspartate Levels in Prefrontal Cortices in Pediatric Bipolar Disorder: A (Superscript 1]H Magnetic Resonance Spectroscopy Study

    ERIC Educational Resources Information Center

    Caetano, Sheila C.; Olvera, Rene L.; Hatch, John P.; Sanches, Marsal; Chen, Hua Hsuan; Nicoletti, Mark; Stanley, Jeffrey A.; Fonseca, Manoela; Hunter, Kristina; Lafer, Beny; Pliszka, Steven R.; Soares, Jair C.

    2011-01-01

    Objective: The few studies applying single-voxel [superscript 1]H spectroscopy in children and adolescents with bipolar disorder (BD) have reported low "N"-acetyl-aspartate (NAA) levels in the dorsolateral prefrontal cortex (DLPFC), and high myo-inositol/phosphocreatine plus creatine (PCr+Cr) ratios in the anterior cingulate. The aim of this study…

  10. Lower "N"-Acetyl-Aspartate Levels in Prefrontal Cortices in Pediatric Bipolar Disorder: A (Superscript 1]H Magnetic Resonance Spectroscopy Study

    ERIC Educational Resources Information Center

    Caetano, Sheila C.; Olvera, Rene L.; Hatch, John P.; Sanches, Marsal; Chen, Hua Hsuan; Nicoletti, Mark; Stanley, Jeffrey A.; Fonseca, Manoela; Hunter, Kristina; Lafer, Beny; Pliszka, Steven R.; Soares, Jair C.

    2011-01-01

    Objective: The few studies applying single-voxel [superscript 1]H spectroscopy in children and adolescents with bipolar disorder (BD) have reported low "N"-acetyl-aspartate (NAA) levels in the dorsolateral prefrontal cortex (DLPFC), and high myo-inositol/phosphocreatine plus creatine (PCr+Cr) ratios in the anterior cingulate. The aim of this study…

  11. Magnetic resonance spectroscopy reveals oral Lactobacillus promotion of increases in brain GABA, N-acetyl aspartate and glutamate.

    PubMed

    Janik, Rafal; Thomason, Lynsie A M; Stanisz, Andrew M; Forsythe, Paul; Bienenstock, John; Stanisz, Greg J

    2016-01-15

    The gut microbiome has been shown to regulate the development and functions of the enteric and central nervous systems. Its involvement in the regulation of behavior has attracted particular attention because of its potential translational importance in clinical disorders, however little is known about the pathways involved. We previously have demonstrated that administration of Lactobacillus rhamnosus (JB-1) to healthy male BALB/c mice, promotes consistent changes in GABA-A and -B receptor sub-types in specific brain regions, accompanied by reductions in anxiety and depression-related behaviors. In the present study, using magnetic resonance spectroscopy (MRS), we quantitatively assessed two clinically validated biomarkers of brain activity and function, glutamate+glutamine (Glx) and total N-acetyl aspartate+N-acetyl aspartyl glutamic acid (tNAA), as well as GABA, the chief brain inhibitory neurotransmitter. Mice received 1×10(9) cfu of JB-1 per day for 4weeks and were subjected to MRS weekly and again 4weeks after cessation of treatment to ascertain temporal changes in these neurometabolites. Baseline concentrations for Glx, tNAA and GABA were equal to 10.4±0.3mM, 8.7±0.1mM, and 1.2±0.1mM, respectively. Delayed increases were first seen for Glx (~10%) and NAA (~37%) at 2weeks which persisted only to the end of treatment. However, Glx was still elevated 4weeks after treatment had ceased. Significantly elevated GABA (~25%) was only seen at 4weeks. These results suggest specific metabolic pathways in our pursuit of mechanisms of action of psychoactive bacteria. They also offer through application of standard clinical neurodiagnostic techniques, translational opportunities to assess biomarkers accompanying behavioral changes induced by alterations in the gut microbiome. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  12. Cortical N-acetyl aspartate is a predictor of long-term clinical disability in multiple sclerosis.

    PubMed

    Wu, Xingchen; Hanson, Lars Grüner; Skimminge, Arnold; Sorensen, Per Soelberg; Paulson, Olaf Bjarne; Mathiesen, Henrik Kahr; Blinkenberg, Morten

    2014-08-01

    To evaluate the prognostic value of the cortical N-acetyl aspartate to creatine ratio (NAA/Cr) in early relapsing-remitting multiple sclerosis (RRMS). Sixteen patients with newly diagnosed RRMS were studied by serial MRI and MR spectroscopic imaging (MRSI) once every 6 months for 24 months. Clinical examinations, including the expanded disability status scale (EDSS), were performed at baseline, month 24, and at year 7. Baseline cortical NAA/Cr correlated inversely with EDSS at month 24 (r  =  -0·61, P < 0·05), and patients with EDSS ≧ 4 had a lower baseline cortical NAA/Cr compared to those with EDSS less than 4 (P < 0·05). Baseline cortical NAA/Cr also correlated inversely with EDSS at the 7-year follow-up (r  =  -0·56, P < 0·05), and patients with EDSS ≧ 4 had a lower baseline cortical NAA/Cr compared to those with EDSS less than 4 (P < 0·05). Baseline brain parenchymal fraction (BPF) correlated inversely with EDSS at month 24 (r  =  -0·61, P < 0·05), but not with EDSS at year 7. Cortical NAA/Cr in early RRMS correlated with clinical disability after 2 and 7 years and may be used as a predictor of long-term disease outcome.

  13. Higher visceral fat is associated with lower cerebral N-acetyl-aspartate ratios in middle-aged adults.

    PubMed

    Kaur, Sonya; Birdsill, Alex C; Steward, Kayla; Pasha, Evan; Kruzliak, Peter; Tanaka, Hirofumi; Haley, Andreana P

    2017-01-31

    Excessive adipose tissue, particularly with a central distribution, consists of visceral fat, which is metabolically active and could impinge upon central nervous system functioning. The aim of the current study was to examine levels of visceral adiposity in relation to key cerebral metabolite ratios localized in the occipitoparietal grey matter. Seventy-three adults, aged between 40 and 60 years, underwent structural magnetic resonance imaging and single voxel (1)H Magnetic Resonance Spectroscopy ((1)H MRS). Visceral fat was assessed using Dual Energy X Ray Absorptiometry (DXA). Individuals with higher visceral fat mass and volume had significantly lower ratios of N-acetyl-aspartate to total creatine (phosphocreatine + creatine, PCr + Cr) (NAA/PCr + Cr) (β = -0.29, p = 0.03, β = -0.28, p = 0.04). They also had significantly higher ratios of myo-inositol to total creatine (mI/PCr + Cr ) (β = 0.36, p = 0.01, β = 0.36, p = 0.01). Visceral fat mass and volume were not significantly related to ratios of glutamate to total creatine (Glu/PCr + Cr). While future studies are necessary, these results indicate central adiposity is associated with metabolic changes that could impinge upon the central nervous system in middle age.

  14. The ratio of N-acetyl aspartate to glutamate correlates with disease duration of amyotrophic lateral sclerosis.

    PubMed

    Sako, Wataru; Abe, Takashi; Izumi, Yuishin; Harada, Masafumi; Kaji, Ryuji

    2016-05-01

    Glutamate (Glu)-induced excitotoxicity has been implicated in the neuronal loss of amyotrophic lateral sclerosis. To test the hypothesis that Glu in the primary motor cortex contributes to disease severity and/or duration, the Glu level was investigated using MR spectroscopy. Seventeen patients with amyotrophic lateral sclerosis were diagnosed according to the El Escorial criteria for suspected, possible, probable or definite amyotrophic lateral sclerosis, and enrolled in this cross-sectional study. We measured metabolite concentrations, including N-acetyl aspartate (NAA), creatine, choline, inositol, Glu and glutamine, and performed partial correlation between each metabolite concentration or NAA/Glu ratio and disease severity or duration using age as a covariate. Considering our hypothesis that Glu is associated with neuronal cell death in amyotrophic lateral sclerosis, we investigated the ratio of NAA to Glu, and found a significant correlation between NAA/Glu and disease duration (r=-0.574, p=0.02). The "suspected" amyotrophic lateral sclerosis patients showed the same tendency as possible, probable and definite amyotrophic lateral sclerosis patients in regard to correlation of NAA/Glu ratio with disease duration. The other metabolites showed no significant correlation. Our findings suggested that glutamatergic neurons are less vulnerable compared to other neurons and this may be because inhibitory receptors are mainly located presynaptically, which supports the notion of Glu-induced excitotoxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Early increase in marker of neuronal integrity with antidepressant treatment of major depression: 1H-magnetic resonance spectroscopy of N-acetyl-aspartate

    PubMed Central

    Taylor, Matthew J.; Godlewska, Beata R.; Norbury, Ray; Selvaraj, Sudhakar; Near, Jamie; Cowen, Philip J.

    2012-01-01

    Increasing interest surrounds potential neuroprotective or neurotrophic actions of antidepressants. While growing evidence points to important early clinical and neuropsychological effects of antidepressants, the time-course of any effect on neuronal integrity is unclear. This study used magnetic resonance spectroscopy to assess effects of short-term treatment with escitalopram on N-acetyl-aspartate (NAA), a marker of neuronal integrity. Thirty-nine participants with major depression were randomly assigned to receive either 10 mg escitalopram or placebo daily in a double-blind, parallel group design. On the seventh day of treatment, PRESS data were obtained from a 30×30×20 mm voxel placed in medial frontal cortex. Age and gender-matched healthy controls who received no treatment were also scanned. Levels of NAA were significantly higher in patients treated with escitalopram than in either placebo-treated patients (p<0.01) or healthy controls (p<0.01). Our findings are consistent with the proposition that antidepressant treatment in depressed patients can produce early changes in neuronal integrity. PMID:22449253

  16. Early increase in marker of neuronal integrity with antidepressant treatment of major depression: 1H-magnetic resonance spectroscopy of N-acetyl-aspartate.

    PubMed

    Taylor, Matthew J; Godlewska, Beata R; Norbury, Ray; Selvaraj, Sudhakar; Near, Jamie; Cowen, Philip J

    2012-11-01

    Increasing interest surrounds potential neuroprotective or neurotrophic actions of antidepressants. While growing evidence points to important early clinical and neuropsychological effects of antidepressants, the time-course of any effect on neuronal integrity is unclear. This study used magnetic resonance spectroscopy to assess effects of short-term treatment with escitalopram on N-acetyl-aspartate (NAA), a marker of neuronal integrity. Thirty-nine participants with major depression were randomly assigned to receive either 10 mg escitalopram or placebo daily in a double-blind, parallel group design. On the seventh day of treatment, PRESS data were obtained from a 30×30×20 mm voxel placed in medial frontal cortex. Age and gender-matched healthy controls who received no treatment were also scanned. Levels of NAA were significantly higher in patients treated with escitalopram than in either placebo-treated patients (p<0.01) or healthy controls (p<0.01). Our findings are consistent with the proposition that antidepressant treatment in depressed patients can produce early changes in neuronal integrity.

  17. The age dependence of T2 relaxation times of N-acetyl aspartate, creatine and choline in the human brain at 3 and 4T.

    PubMed

    Jiru, F; Skoch, A; Wagnerova, D; Dezortova, M; Viskova, J; Profant, O; Syka, J; Hajek, M

    2016-03-01

    Knowledge of the T2 age dependence is of importance for MRS clinical studies involving subject groups with a wide age range. A number of studies have focused on the age dependence of T2 values in the human brain, with rather conflicting results. The aim of this study was to analyze the age dependence of T2 values of N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho) in the human brain using data acquired at 3T and 4T and to assess the influence of the macromolecule (MM) baseline handling on the obtained results. Two distinct groups of young and elderly controls have been measured at 3T (TE = 30-540 ms, 9 young and 11 elderly subjects) and 4T (TE = 10-180 ms, 18 young and 14 elderly subjects) using single-voxel spectroscopy. In addition, MM spectra were measured from two subjects using the inversion-recovery technique at 4T. All spectra were processed with LCModel using basis sets with different MM signals (measured or simulated) and also with MM signals included for a different TE range. Individual estimated T2 values were statistically analyzed using the R programming language for the age dependence of T2 values as well as the influence of the MM baseline handling. A significant decrease of T2 values of NAA and Cr in elderly subjects compared with young subjects was confirmed. The same trend was observed for Cho. Significantly higher T2 values calculated using the measured MM baseline for all studied metabolites at 4T were observed for both young and elderly subjects. To conclude, while the handling of MM and lipid signals may have a significant effect on estimated T2 values, we confirmed the age dependence of T2 values of NAA and Cr and the same trend for Cho in the human brain. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Relationship of executive functioning deficits to N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) in youth with bipolar disorder.

    PubMed

    Huber, Rebekah S; Kondo, Douglas G; Shi, Xian-Feng; Prescot, Andrew P; Clark, Elaine; Renshaw, Perry F; Yurgelun-Todd, Deborah A

    2017-08-01

    Although cognitive deficits in bipolar disorder (BD) have been repeatedly observed, our understanding of these impairments at a mechanistic level remains limited. Few studies that investigated cognitive impairments in bipolar illness have examined the association with brain biochemistry. This pilot study utilized proton magnetic resonance spectroscopy ((1)H-MRS) to evaluate the relationship between neurocognitive performance and brain metabolites in youth with BD. Thirty participants, twenty depressed BD participants and ten healthy comparison participants, ages 13-21, completed mood and executive function measures. (1)H-MRS data were also acquired from the anterior cingulate cortex (ACC) using two-dimensional (2D) J-resolved (1)H-MRS sequence. Proton metabolites including N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) were quantified for both groups. Participants with BD performed significantly lower on executive functioning measures than comparison participants. There were significant positive correlations between Wisconsin Card Sorting Test (WCST) performance and NAA (p < .001) and GABA (p < .01) in the ACC in bipolar youth, such that as WCST performance increased, both NAA and GABA levels increased. Small sample size and lack of control for medications. These findings build on previous observations of biochemical alterations associated with BD and indicate that executive functioning deficits in bipolar youth are correlated with NAA and GABA. These results suggest that cognitive deficits occur early in the course of illness and may reflect risk factors associated with altered neurochemistry. Further investigation of the relationship between brain metabolites and cognition in BD may lead to important information for developing novel, targeted interventions. Copyright © 2017. Published by Elsevier B.V.

  19. A multi-matrix HILIC-MS/MS method for the quantitation of endogenous small molecule neurological biomarker N-acetyl aspartic acid (NAA).

    PubMed

    Sangaraju, Dewakar; Shahidi-Latham, Sheerin K; Burgess, Braydon L; Dean, Brian; Ding, Xiao

    2017-03-14

    A multi-matrix hydrophilic interaction liquid chromatography tandem mass spectrometric method (HILIC-MS/MS) was developed for the quantitation of N-Acetyl Aspartic acid (NAA) using stable isotope labeled internal standard, D3-NAA in various biological matrices such as human plasma, human CSF, mouse plasma, brain and spinal cord. A high throughput 96-well plate format supported liquid extraction (SLE) procedure was developed and used for sample preparation. Mass spectrometric analysis of NAA was performed using selected reaction monitoring transitions in positive electrospray ionization mode. As NAA is endogenously present, a surrogate matrix approach was used for quantitation of NAA and the method was qualified over linear calibration curve range of 0.01-10μg/mL. Intra and inter assay precision indicated by percent relative standard deviation (%RSD) was less than 7.1% for low, medium, medium high and high QCs. The accuracy of the method ranged from 92.6-107.0% of nominal concentration for within-run and between-run for the same QCs. Extraction recovery of NAA and D3-NAA was greater than 76%. Stability of NAA was established in the above biological matrices under bench top (RT, 5h), freeze thaw (-20±10°C, 3 cycles) and moues/human plasma sample collection (Wet ice, RT) conditions. HILIC-MS/MS method was then used to quantify and compare the NAA levels in human plasma and CSF of ALS patients versus control human subjects. NAA CSF levels in control human subjects (73.3±31.0ng/mL,N=10) were found to be slightly higher than ALS patients (46.1±22.6ng/mL, N=10) (P=0.04). No differences were observed in NAA plasma levels in human control subjects (49.7±13.8ng/mL,N=9) as compared to ALS patients (49.6±8.1ng/mL, N=10) (P=0.983). NAA endogenous concentrations in mouse plasma, brain and spinal cord were found to be 243.8±56.8ng/mL (N=6), 1029.8±115.2μg/g tissue weight (N=5) and 487.6±178.4μg/g tissue weight (N=5) respectively.

  20. N-acetyl-L-aspartic acid-N'-methylamide with side-chain orientation capable of external hydrogen bonding . Backbone and side-chain folding, studied at the DFT level of quantum theory

    NASA Astrophysics Data System (ADS)

    Koo, J. C. P.; Chass, G. A.; Perczel, A.; Farkas, Ö.; Varro, A.; Torday, L. L.; Papp, J. Gy.; Csizmadia, I. G.

    2002-09-01

    In this study, we generated and analyzed the side-chain conformational potential energy hypersurfaces for each of the nine possible backbone conformers for N-acetyl-L-aspartic acid-N' methylamide. We found a total of 27 out of the 81 possible conformers optimized at the B3LYP/6-31G(d) level of theory. The relative energies, as well as the stabilization energies exerted by the side-chain on the backbone, have been calculated for each of the 27 optimized conformers at this level of theory. Various backbone-backbone (N H{\\cdot}{\\cdot}{\\cdot}O=C) and backbone-side-chain (N H{\\cdot}{\\cdot}{\\cdot}O=C; N H{\\cdot}{\\cdot}{\\cdot}OH) hydrogen bonds were analyzed. The appearance of the notoriously absent \\varepsilon_L backbone conformer may be attributed to such side-chain-backbone (SC/BB) and backbone-backbone (BB/BB) hydrogen bonds.

  1. Structure of the O-polysaccharide of Providencia stuartii O4 containing 4-(N-acetyl-L-aspart-4-yl)amino-4,6-dideoxy-D-glucose.

    PubMed

    Kocharova, Nina A; Torzewska, Agnieszka; Zatonsky, George V; Błaszczyk, Aleksandra; Bystrova, Olga V; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2004-01-22

    The O-polysaccharide of Providencia stuartii O4 was obtained by mild acid degradation of the lipopolysaccharide, and the following structure of the pentasaccharide repeating unit was established: [structure: see text] where D-Qui4N(L-AspAc) is 4-(N-acetyl-L-aspart-4-yl)amino-4,6-dideoxy-D-glucose, which has not been hitherto found in bacterial polysaccharides. Structural studies were performed using sugar and methylation analyses, Smith degradation and NMR spectroscopy, including conventional 2D 1H,1H COSY, TOCSY, NOESY and 1H,13C HSQC experiments as well as COSY and NOESY experiments run in an H(2)O-D(2)O mixture to reveal correlations for NH protons.

  2. Evaluation of the Lactate-to-N-Acetyl-aspartate Ratio Defined With Magnetic Resonance Spectroscopic Imaging Before Radiation Therapy as a New Predictive Marker of the Site of Relapse in Patients With Glioblastoma Multiforme

    SciTech Connect

    Deviers, Alexandra; Ken, Soléakhéna; Filleron, Thomas; Rowland, Benjamin; Laruelo, Andrea; Catalaa, Isabelle; Lubrano, Vincent; Celsis, Pierre; and others

    2014-10-01

    Purpose: Because lactate accumulation is considered a surrogate for hypoxia and tumor radiation resistance, we studied the spatial distribution of the lactate-to-N-acetyl-aspartate ratio (LNR) before radiation therapy (RT) with 3D proton magnetic resonance spectroscopic imaging (3D-{sup 1}H-MRSI) and assessed its impact on local tumor control in glioblastoma (GBM). Methods and Materials: Fourteen patients with newly diagnosed GBM included in a phase 2 chemoradiation therapy trial constituted our database. Magnetic resonance imaging (MRI) and MRSI data before RT were evaluated and correlated to MRI data at relapse. The optimal threshold for tumor-associated LNR was determined with receiver-operating-characteristic (ROC) curve analysis of the pre-RT LNR values and MRI characteristics of the tumor. This threshold was used to segment pre-RT normalized LNR maps. Two spatial analyses were performed: (1) a pre-RT volumetric comparison of abnormal LNR areas with regions of MRI-defined lesions and a choline (Cho)-to- N-acetyl-aspartate (NAA) ratio ≥2 (CNR2); and (2) a voxel-by-voxel spatial analysis of 4,186,185 voxels with the intention of evaluating whether pre-RT abnormal LNR areas were predictive of the site of local recurrence. Results: A LNR of ≥0.4 (LNR-0.4) discriminated between tumor-associated and normal LNR values with 88.8% sensitivity and 97.6% specificity. LNR-0.4 voxels were spatially different from those of MRI-defined lesions, representing 44% of contrast enhancement, 64% of central necrosis, and 26% of fluid-attenuated inversion recovery (FLAIR) abnormality volumes before RT. They extended beyond the overlap with CNR2 for most patients (median: 20 cm{sup 3}; range: 6-49 cm{sup 3}). LNR-0.4 voxels were significantly predictive of local recurrence, regarded as contrast enhancement at relapse: 71% of voxels with a LNR-0.4 before RT were contrast enhanced at relapse versus 10% of voxels with a normal LNR (P<.01). Conclusions: Pre-RT LNR-0.4 in GBM

  3. Reduction of hippocampal N-acetyl aspartate level in aged APP(Swe)/PS1(dE9) transgenic mice is associated with degeneration of CA3 pyramidal neurons.

    PubMed

    Xu, Wei; Zhan, Yanqiang; Huang, Wei; Wang, Xuxia; Zhang, Sumin; Lei, Hao

    2010-11-01

    Age-related metabolic changes in the hippocampus of APP(Swe)/PS1(dE9) mice were measured with long echo-time in vivo (1)H-magnetic resonance spectroscopy ((1)H-MRS). Thioflavine S staining and Nissl staining were used to characterize deposition of Aβ aggregates and neuronal degeneration in the transgenic animals, respectively. The results showed that the APP(Swe)/PS1(dE9) mice had significantly decreased hippocampal N-acetyl aspartate (NAA)/total creatine (tCr) level at 16 months of age, which was associated with degeneration of and intracellular deposition of thioflavine S-positive materials in hippocampal CA3 pyramidal neurons. The results of this study provide direct evidence showing association among Aβ pathology (intracellular deposition of thioflavine S-positive materials), neuronal degeneration, and metabolic changes observable with in vivo (1)H-MRS in the hippocampus of APP(Swe)/PS1(dE9) mice.

  4. Structure of the O-polysaccharide and serological cross-reactivity of the Providencia stuartii O33 lipopolysaccharide containing 4-(N-acetyl-D-aspart-4-yl)amino-4,6-dideoxy-D-glucose.

    PubMed

    Torzewska, Agnieszka; Kocharova, Nina A; Zatonsky, George V; Blaszczyk, Aleksandra; Bystrova, Olga V; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2004-06-01

    The O-polysaccharide of Providencia stuartii O33 was obtained by mild acid degradation of the lipopolysaccharide and the following structure of the tetrasaccharide repeating unit was established: -->6)-alpha-D-GlcpNAc-(1-->4)-alpha-D-GalpA-(1-->3)-alpha-D-GlcpNAc-(1-->3)-beta-D-Quip4N(Ac-D-Asp)-(1-->, where d-Qui4N(Ac-D-Asp) is 4-(N-acetyl-D-aspart-4-yl)amino-4,6-dideoxy-D-glucose. Structural studies were performed using sugar and methylation analyses and NMR spectroscopy, including conventional 2D 1H, 1H COSY, TOCSY, NOESY and 1H, 13C HSQC experiments as well as COSY and NOESY experiments in an H2O-D2O mixture to reveal correlations for NH protons. The O-polysaccharide of P. stuartii O33 shares an alpha-D-GlcpNAc-(1-->3)-beta-D-Quip4N(Ac-D-Asp) epitope with that of Proteus mirabilis O38, which seems to be responsible for a marked serological cross-reactivity of anti-P. stuartii O33 serum with the lipopolysaccharide of the latter bacterium. P. stuartii O33 is serologically related also to P. stuartii O4, whose O-polysaccharide contains a lateral beta-D-Qui4N(Ac-L-Asp) residue.

  5. Choline-to-N-acetyl aspartate and lipids-lactate-to-creatine ratios together with age assemble a significant Cox's proportional-hazards regression model for prediction of survival in high-grade gliomas.

    PubMed

    Roldan-Valadez, Ernesto; Rios, Camilo; Motola-Kuba, Daniel; Matus-Santos, Juan; Villa, Antonio R; Moreno-Jimenez, Sergio

    2016-11-01

    A long-lasting concern has prevailed for the identification of predictive biomarkers for high-grade gliomas (HGGs) using MRI. However, a consensus of which imaging parameters assemble a significant survival model is still missing in the literature; we investigated the significant positive or negative contribution of several MR biomarkers in this tumour prognosis. A retrospective cohort of supratentorial HGGs [11 glioblastoma multiforme (GBM) and 17 anaplastic astrocytomas] included 28 patients (9 females and 19 males, respectively, with a mean age of 50.4 years, standard deviation: 16.28 years; range: 13-85 years). Oedema and viable tumour measurements were acquired using regions of interest in T1 weighted, T2 weighted, fluid-attenuated inversion recovery, apparent diffusion coefficient (ADC) and MR spectroscopy (MRS). We calculated Kaplan-Meier curves and obtained Cox's proportional hazards. During the follow-up period (3-98 months), 17 deaths were recorded. The median survival time was 1.73 years (range, 0.287-8.947 years). Only 3 out of 20 covariates (choline-to-N-acetyl aspartate and lipids-lactate-to-creatine ratios and age) showed significance in explaining the variability in the survival hazards model; score test: χ(2) (3) = 9.098, p = 0.028. MRS metabolites overcome volumetric parameters of peritumoral oedema and viable tumour, as well as tumour region ADC measurements. Specific MRS ratios (Cho/Naa, L-L/Cr) might be considered in a regular follow-up for these tumours. Advances in knowledge: Cho/Naa ratio is the strongest survival predictor with a log-hazard function of 2.672 in GBM. Low levels of lipids-lactate/Cr ratio represent up to a 41.6% reduction in the risk of death in GBM.

  6. N-ACETYL GROUPS IN VITELLENIN,

    DTIC Science & Technology

    The presence of acetyl groups in vitellenin was confirmed by hydrazinolysis according to the DNP method of Phillips. After hydrazinolysis of 10-30...hydrazinolysis at room temperature for 1 hour, vitellenin contains N- acetyl , but no Oacetyl, groups. (Author)

  7. Comparative analysis of pharmacological treatments with N-acetyl-DL-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

    PubMed

    Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

    2015-12-15

    Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. N-acetyl endorphin in rat spermatogonia and primary spermatocytes.

    PubMed Central

    Cheng, M C; Clements, J A; Smith, A I; Lolait, S J; Funder, J W

    1985-01-01

    In previous reports modest levels of beta-endorphin have been found by radioimmunoassay in rat testis, and localized by immunofluorescence to the interstitial cells. We have confirmed these previous reports and extended them by showing that the majority of testicular endorphins are acetylated forms, N-acetyl gamma-endorphin, N-acetyl alpha-endorphin, and N-acetyl beta-endorphin1-27. In addition, N-acetylated endorphins are not found in interstitial cells, but are confined to spermatogonia and primary spermatocytes. Images PMID:3156881

  9. N-ACETYL-β-GLUCOSAMINIDASE ACTIVITY IN SERUM DURING PREGNANCY

    PubMed Central

    Walker, P. G.; Woollen, Mary E.; Pugh, Doreen

    1960-01-01

    A spectrophotometric method for the estimation of N-acetyl-β-glucosaminidase in serum has been devised. Sera from normal adult males and females showed similar levels of activity. The activity in serum rose progressively during pregnancy and fell rapidly after parturition to normal levels. This change resembled closely that which occurs in serum β-glucuronidase. Placenta showed a moderate and chorion a high level of N-acetyl-β-glucosaminidase. High N-acetyl-β-glucosaminidase activity was demonstrated histochemically in decidual cells. The functions of N-acetyl-β-glucosaminidase and β-glucuronidase and factors influencing their activity are discussed. Images PMID:13782743

  10. The structure- and metal-dependent activity of Escherichia coli PgaB provides insight into the partial de-N-acetylation of poly-β-1,6-N-acetyl-D-glucosamine.

    PubMed

    Little, Dustin J; Poloczek, Joanna; Whitney, John C; Robinson, Howard; Nitz, Mark; Howell, P Lynne

    2012-09-07

    Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In Escherichia coli, partial de-N-acetylation of the exopolysaccharide poly-β-1,6-N-acetyl-D-glucosamine (PNAG) by the periplasmic protein PgaB is required for polysaccharide intercellular adhesin-dependent biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of PgaB in complex with Ni(2+) and Fe(3+) have been determined to 1.9 and 2.1 Å resolution, respectively, and its activity on β-1,6-GlcNAc oligomers has been characterized. The structure of PgaB reveals two (β/α)(x) barrel domains: a metal-binding de-N-acetylase that is a member of the family 4 carbohydrate esterases (CE4s) and a domain structurally similar to glycoside hydrolases. PgaB displays de-N-acetylase activity on β-1,6-GlcNAc oligomers but not on the β-1,4-(GlcNAc)(4) oligomer chitotetraose and is the first CE4 member to exhibit this substrate specificity. De-N-acetylation occurs in a length-dependent manor, and specificity is observed for the position of de-N-acetylation. A key aspartic acid involved in de-N-acetylation, normally seen in other CE4s, is missing in PgaB, suggesting that the activity of PgaB is attenuated to maintain the low levels of de-N-acetylation of PNAG observed in vivo. The metal dependence of PgaB is different from most CE4s, because PgaB shows increased rates of de-N-acetylation with Co(2+) and Ni(2+) under aerobic conditions, and Co(2+), Ni(2+) and Fe(2+) under anaerobic conditions, but decreased activity with Zn(2+). The work presented herein will guide inhibitor design to combat biofilm formation by E. coli and potentially a wide range of medically relevant bacteria producing polysaccharide intercellular adhesin-dependent biofilms.

  11. The Structure- and Metal-dependent Activity of Escherichia coli PgaB Provides Insight into the Partial De-N-acetylation of Poly-β-1,6-N-acetyl-d-glucosamine*

    PubMed Central

    Little, Dustin J.; Poloczek, Joanna; Whitney, John C.; Robinson, Howard; Nitz, Mark; Howell, P. Lynne

    2012-01-01

    Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In Escherichia coli, partial de-N-acetylation of the exopolysaccharide poly-β-1,6-N-acetyl-d-glucosamine (PNAG) by the periplasmic protein PgaB is required for polysaccharide intercellular adhesin-dependent biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of PgaB in complex with Ni2+ and Fe3+ have been determined to 1.9 and 2.1 Å resolution, respectively, and its activity on β-1,6-GlcNAc oligomers has been characterized. The structure of PgaB reveals two (β/α)x barrel domains: a metal-binding de-N-acetylase that is a member of the family 4 carbohydrate esterases (CE4s) and a domain structurally similar to glycoside hydrolases. PgaB displays de-N-acetylase activity on β-1,6-GlcNAc oligomers but not on the β-1,4-(GlcNAc)4 oligomer chitotetraose and is the first CE4 member to exhibit this substrate specificity. De-N-acetylation occurs in a length-dependent manor, and specificity is observed for the position of de-N-acetylation. A key aspartic acid involved in de-N-acetylation, normally seen in other CE4s, is missing in PgaB, suggesting that the activity of PgaB is attenuated to maintain the low levels of de-N-acetylation of PNAG observed in vivo. The metal dependence of PgaB is different from most CE4s, because PgaB shows increased rates of de-N-acetylation with Co2+ and Ni2+ under aerobic conditions, and Co2+, Ni2+ and Fe2+ under anaerobic conditions, but decreased activity with Zn2+. The work presented herein will guide inhibitor design to combat biofilm formation by E. coli and potentially a wide range of medically relevant bacteria producing polysaccharide intercellular adhesin-dependent biofilms. PMID:22810235

  12. In vivo N-acetyl cysteine reduce hepatocyte death by induced acetaminophen

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Ju; Li, Feng-Chieh; Wang, Sheng-Shun; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2011-07-01

    Acetaminophen (APAP) is the famous drug in global, and taking overdose Acetaminophen will intake hepatic cell injure. Desptie substantial progress in our understanding of the mechanism of hepatocellular injury during the last 40 years, many aspects of the pathophysiology are still unknown or controversial.1 In this study, mice are injected APAP overdose to damage hepatocyte. APAP deplete glutathione and ATP of cell, N-Acetyl Cysteine (NAC) plays an important role to protect hepatocytes be injury. N-Acetyl Cysteine provides mitochondrial to produce glutathione to release drug effect hepatocyte. By 6-carboxyfluorescein diacetate (6-CFDA) metabolism in vivo, glutathione keep depleting to observe the hepatocyte morphology in time. Without NAC, cell necrosis increase to plasma membrane damage to release 6-CFDA, that's rupture. After 6-CFDA injection, fluorescence will be retained in hepatocyte. For cell retain with NAC and without NAC are almost the same. With NAC, the number of cell rupture decreases about 75%.

  13. Chitosan Molecular Structure as a Function of N-Acetylation

    SciTech Connect

    Franca, Eduardo F.; Freitas, Luiz C.; Lins, Roberto D.

    2011-07-01

    Molecular dynamics simulations have been carried out to characterize the structure and solubility of chitosan nanoparticle-like structures as a function of the deacetylation level (0, 40, 60, and 100%) and the spatial distribution of the N-acetyl groups in the particles. The polysaccharide chains of highly N-deacetylated particles where the N-acetyl groups are uniformly distributed present a high flexibility and preference for the relaxed two-fold helix and five-fold helix motifs. When these groups are confined to a given region of the particle, the chains adopt preferentially a two-fold helix with f and w values close to crystalline chitin. Nanoparticles with up to 40% acetylation are moderately soluble, forming stable aggregates when the N-acetyl groups are unevenly distributed. Systems with 60% or higher N-acetylation levels are insoluble and present similar degrees of swelling regardless the distribution of their N-acetyl groups. Overall particle solvation is highly affected by electrostatic forces resulting from the degree of acetylation. The water mobility and orientation around the polysaccharide chains affects the stability of the intramolecular O3- HO3(n) ... O5(n+ 1) hydrogen bond, which in turn controls particle aggregation.

  14. N-Acetylation of Glucosamine-6-Phosphate in Leuconostoc mesenteroides

    PubMed Central

    DeMoss, R. D.; Moser, K.

    1969-01-01

    A partially purified enzyme (120-fold) from Leuconostoc mesenteroides catalyzed the reversible N-acetylation of d-glucosamine-6-phosphate. Coenzyme A was not required and inhibited the reaction rate. Neither d-glucosamine nor N-acetyl-d-glucosamine served as a substrate for the reversible reaction. The enzyme preparation retained 50% of its original activity after 5 min at 100 C. The Km for acetate was 7.7 × 10−2m in the presence of 2 × 10−2md-glucosamine-6-phosphate. The Km for d-glucosamine-6-phosphate was 5.0 × 10−3m in the presence of 0.64 m acetate. The product of the reaction was characterized by comparison with N-acetyl-d-glucosamine-6-phosphate prepared by enzymatic phosphorylation of N-acetyl-d-glusamine. The characterization tests were: chromatographic migration, acid hydrolysis, enzymatic dephosphorylation, sodium borohydride reduction, and periodate oxidation. The equilibrium constant for the reaction was about 7.5 m for the expression K = (d-glucosamine-6-phosphate)(acetate)/N-acetyl-d-glucosamine-6-phosphate. The standard free energy of the reaction was approximately 1,200 cal per mole. PMID:5781575

  15. Quantification of N-Acetyl Aspartyl Glutamate in Human Brain using Proton Magnetic Resonance Spectroscopy at 7 T

    NASA Astrophysics Data System (ADS)

    Elywa, M.

    2015-07-01

    The separation of N-acetyl aspartyl glutamate (NAAG) from N-acetyl aspartate (NAA) and other metabolites, such as glutamate, by in vivo proton magnetic resonance spectroscopy at 7 T is described. This method is based on the stimulated echo acquisition mode (STEAM), with short and long echo time (TE) and allows quantitative measurements of NAAG in the parietal and pregenual anterior cingulate cortex (pgACC) of human brain. Two basesets for the LCModel have been established using nuclear magnetic resonance simulator software (NMR-SIM). Six healthy volunteers (age 25-35 years) have been examined at 7 T. It has been established that NAAG can be separated and quantified in the parietal location and does not get quantified in the pgACC location when using a short echo time, TE = 20 ms. On the other hand, by using a long echo time, TE = 74 ms, NAAG can be quantified in pgACC structures.

  16. [N-ACETYL-β-D-GLUCOSAMINIDASE OF VIBRIO CHOLERAE].

    PubMed

    Duvanova, O V; Mishankin, B N; Vodopianov, A S; Sorokin, V M

    2016-01-01

    Study N-acetyl-β-D-glucosaminidase (chitobiase) (EC 3.2.1.30) in strains of Vibrio cholerae of O1/non-O1 serogroups of various origin, that is a component of chitinolytic complex taking into account object of isolation and epidemiologic significance of strains. Cultures of V. cholerae O1/non-O1 serogroup strains were obtained from the museum of live culture of Rostov RIPC. Enzymatic activity analysis was carried out in Hitachi F-2500 fluorescent spectrophotometer using FL Solutions licensed software. NCBI databases were used during enzyme characteristics. N-acetyl-β-D-glucosaminidase in Vcholerae O1/non-O1 serogroup strains was detected, purified by column chromatography, studied and characterized by a number of physical-chemical and biological properties. Comparative computer analysis of amino acid sequence of N-acetyl-β-D-glucosaminidases of V. cholerae (VC2217 gene), Serratia marcescens etc. has allowed. to attribute the enzyme from V. cholerae to glycosyl-hydrolases (chitobiases) of family 20 and classify it according to enzyme nomenclature as EC 3.2.1.30. N-acetyl-β-D-glucosaminidase in V. cholerae of O1/non-O1 serogroups of various origin and epidemiologic significance, participating in chitin utilization was studied and characterized for the first time, and its possible role in biology of cholera causative agent was shown.

  17. Getting a Knack for NAC: N-Acetyl-Cysteine.

    PubMed

    Sansone, Randy A; Sansone, Lori A

    2011-01-01

    N-acetyl-cysteine, N-acetylcysteine, N-acetyl cysteine, and N-acetyl-L-cysteine are all designations for the same compound, which is abbreviated as NAC. NAC is a precursor to the amino acid cysteine, which ultimately plays two key metabolic roles. Through its metabolic contribution to glutathione production, cysteine participates in the general antioxidant activities of the body. Through its role as a modulator of the glutamatergic system, cysteine influences the reward-reinforcement pathway. Because of these functions, NAC may exert a therapeutic effect on psychiatric disorders allegedly related to oxidative stress (e.g., schizophrenia, bipolar disorder) as well as psychiatric syndromes characterized by impulsive/compulsive symptoms (e.g., trichotillomania, pathological nail biting, gambling, substance misuse). While the dosages, pharmacological strategies (monotherapy versus augmentation), and long-term risks are not fully evident, NAC appears to be a promising, relatively low-risk intervention. If so, NAC might be an ideal treatment strategy for a variety of psychiatric conditions in both psychiatric and primary care settings.

  18. Oral Administration of N-Acetyl-D-Glucosamine Polymer Particles Down-Regulates Airway Allergic Responses

    DTIC Science & Technology

    2007-03-01

    AD_________________ Award Number: DAMD17-03-1-0004 TITLE: Oral Administration of N- Acetyl -D...Oral Administration of N- Acetyl -D-Glucosamine Polymer Particles Down-Regulates 5a. CONTRACT NUMBER Airway Allergic Responses...TERMS Childhood asthma, N- acetyl -D-glucosamine polymer, IL-12, GATA-3, T-bet, macrophages, airway hyperreactivity 16. SECURITY CLASSIFICATION OF

  19. N-Acetyl-4-aminophenol (paracetamol), N-acetyl-2-aminophenol and acetanilide in urine samples from the general population, individuals exposed to aniline and paracetamol users.

    PubMed

    Dierkes, Georg; Weiss, Tobias; Modick, Hendrik; Käfferlein, Heiko Udo; Brüning, Thomas; Koch, Holger M

    2014-01-01

    Epidemiological studies suggest associations between the use of N-acetyl-4-aminophenol (paracetamol) during pregnancy and increased risks of reproductive disorders in the male offspring. Previously we have reported a ubiquitous urinary excretion of N-acetyl-4-aminophenol in the general population. Possible sources are (1) direct intake of paracetamol through medication, (2) paracetamol residues in the food chain and (3) environmental exposure to aniline or related substances that are metabolized into N-acetyl-4-aminophenol. In order to elucidate the origins of the excretion of N-acetyl-4-aminophenol in urine and to contribute to the understanding of paracetamol and aniline metabolism in humans we developed a rapid, turbulent-flow HPLC-MS/MS method with isotope dilution for the simultaneous quantification of N-acetyl-4-aminophenol and two other aniline related metabolites, N-acetyl-2-aminophenol and acetanilide. We applied this method to three sets of urine samples: (1) individuals with no known exposure to aniline and also no recent paracetamol medication; (2) individuals after occupational exposure to aniline but no paracetamol medication and (3) paracetamol users. We confirmed the omnipresent excretion of N-acetyl-4-aminophenol. Additionally we revealed an omnipresent excretion of N-acetyl-2-aminophenol. In contrast, acetanilide was only found after occupational exposure to aniline, not in the general population or after paracetamol use. The results lead to four preliminary conclusions: (1) other sources than aniline seem to be responsible for the major part of urinary N-acetyl-4-aminophenol in the general population; (2) acetanilide is a metabolite of aniline in man and a valuable biomarker for aniline in occupational settings; (3) aniline baseline levels in the general population measured after chemical hydrolysis do not seem to originate from acetanilide and hence not from a direct exposure to aniline itself and (4) N-acetyl-2-aminophenol does not seem to be

  20. [Metabolism of N-acetyl-L-aspartate: its diagnostic and prognostic value].

    PubMed

    Martinez, Manuel A; Florenzano, Néstor V; Macchia, Esteban A

    2016-04-16

    Objetivos. Analizar la implicacion clinica del aminoacido N-acetil-L-aspartato (NAA) y el peptido N-acetil-aspartil-glutamato (NAAG) en relacion con su valoracion diagnostica y pronostica mediante espectroscopia de resonancia magnetica. Realizar una revision del metabolismo del NAA y del NAAG, considerando su estructura quimica y fisiologia, en relacion con las variaciones de su concentracion y en correlacion con la clinica. Desarrollo. La revision se divide en dos partes: en una se comprobo que el unico sitio de sintesis del NAA es la mitocondria neuronal, y del NAAG, el citoplasma neuronal; la segunda parte aborda las tecnicas de resonancia magnetica y, particularmente, la espectroscopia. Se analizan diversas patologias en busca de criterios que posibiliten obtener pautas diagnosticas y pronosticas. Conclusiones. El estudio del aminoacido mas abundante del sistema nervioso central (NAA) junto con un producto de su metabolismo, el NAAG, permite en patologias de diversos origenes su diagnostico y seguimiento y facilita la obtencion de datos de densidad de la poblacion celular y vitalidad de esta, de manera que se accede, ademas, al estado funcional de las sinapsis.

  1. Inhibition of N-acetylneuraminate lyase by N-acetyl-4-oxo-D-neuraminic acid.

    PubMed

    Gross, H J; Brossmer, R

    1988-05-09

    We show that the 4-oxo analogue of N-acetyl-D-neuraminic acid strongly inhibits N-acetylneuraminate lyase (NeuAc aldolase, EC 4.1.3.3) from Clostridum perfringens (Ki = 0.025 mM) and Escherichia coli (Ki = 0.15 mM). In each case the inhibition was competitive. N-Acetyl-D-neuraminic acid; N-Acetylneuraminate lyase; N-Acetyl-D-neuraminic acid analog; 5-Acetamido-3,5-dideoxy-beta-D-manno-non-2,4-diulosonic acid; 2-Deoxy-2,3-didehydro-N-acetyl-4-oxo-neuraminic acid; Competitive inhibitor.

  2. A Review on Various Uses of N-Acetyl Cysteine

    PubMed Central

    Mokhtari, Vida; Afsharian, Parvaneh; Shahhoseini, Maryam; Kalantar, Seyed Mehdi; Moini, Ashraf

    2017-01-01

    N-acetyl cysteine (NAC), as a nutritional supplement, is a greatly applied antioxidant in vivo and in vitro. NAC is a precursor of L-cysteine that results in glutathione elevation biosynthesis. It acts directly as a scavenger of free radicals, especially oxygen radicals. NAC is a powerful antioxidant. It is also recommended as a potential treatment option for different disorders resulted from generation of free oxygen radicals. Additionally, it is a protected and endured mucolytic drug that mellows tenacious mucous discharges. It has been used for treatment of various diseases in a direct action or in a combination with some other medications. This paper presents a review on various applications of NAC in treatment of several diseases. PMID:28367412

  3. N-acetyl-L-Cysteine as prophylaxis against sulfur mustard.

    PubMed

    Bobb, Andrew J; Arfsten, Darryl P; Jederberg, Warren W

    2005-01-01

    Sulfur mustard (HD) is a blister agent targeting the eyes, respiratory system, skin, and possibly other organs. Extensive exposure can destroy the immune system by destruction of bone marrow cells. There is no antidote for HD or effective treatment other than rapid decontamination. Clinical trials have demonstrated activity for N-acetyl-L-cysteine (NAC) against a number of significant human pathologies involving free radicals, and animal and tissue studies have suggested efficacy for NAC as a chemoprotectant against many toxic chemicals. Among these are studies demonstrating that NAC significantly reduces the effects of HD and HD simulants, both in cultured cells and animals. Given the historical effectiveness of HD, the lack of any effective treatment, the demonstrated chemoprotective properties of NAC, its low toxicity, the lack of regulatory controls, and the data supporting efficacy against HD effects, we suggest daily oral administration of the maximum safe dose of NAC to personnel entering combat zones.

  4. Regulation of extracellular N-acetyl-D-glucosaminidase production in the entomopathogenic fungus Beauveria bassiana.

    PubMed

    Bidochka, M J; Khachatourians, G G

    1993-01-01

    The entomopathogenic fungus Beauveria bassiana produces two extracellular N-acetylglucosaminidases (NAGase) in liquid medium containing colloidal chitin as the sole source of carbon and nitrogen. To study the regulation of NAGase synthesis, N-acetyl-D-glucosamine (GlcNAc), glucose NH4NO3, or amino acids were added to the colloidal chitin medium and NAGase activity was measured. NAGase synthesis was (i) induced with GlcNAc, and no repression was observed with GlcNAc provided at 2% (w/v); (ii) repressed in the presence of glucose plus NH4NO3; (iii) partially repressed when glucose or NH4NO3 was provided; and (iv) repressed to levels that were < 40% of the control levels when glutamic acid, tyrosine, arginine, proline, valine, and histidine were provided to the colloidal chitin medium. Total NAGase activity levels were > 60% of the control activity when alanine, glycine, isoleucine, aspartic acid, and leucine were tested. It appears that synthesis of NAGase is sensitive to cell energy and the carbon and nitrogen requirements.

  5. Complex N-Acetylation of TriethylenetetramineS⃞

    PubMed Central

    Cerrada-Gimenez, Marc; Weisell, Janne; Hyvönen, Mervi T.; Hee Park, Myung; Alhonen, Leena; Vepsäläinen, Jouko

    2011-01-01

    Triethylenetetramine (TETA) is an efficient copper chelator that has versatile clinical potential. We have recently shown that spermidine/spermine-N1-acetyltransferase (SSAT1), the key polyamine catabolic enzyme, acetylates TETA in vitro. Here, we studied the metabolism of TETA in three different mouse lines: syngenic, SSAT1-overexpressing, and SSAT1-deficient (SSAT1-KO) mice. The mice were sacrificed at 1, 2, or 4 h after TETA injection (300 mg/kg i.p.). We found only N1-acetyltriethylenetetramine (N1AcTETA) and/or TETA in the liver, kidney, and plasma samples. As expected, SSAT1-overexpressing mice acetylated TETA at an accelerated rate compared with syngenic and SSAT1-KO mice. It is noteworthy that SSAT1-KO mice metabolized TETA as syngenic mice did, probably by thialysine acetyltransferase, which had a Km value of 2.5 ± 0.3 mM and a kcat value of 1.3 s−1 for TETA when tested in vitro with the human recombinant enzyme. Thus, the present results suggest that there are at least two N-acetylases potentially metabolizing TETA. However, their physiological significance for TETA acetylation requires further studies. Furthermore, we detected chemical intramolecular N-acetyl migration from the N1 to N3 position of N1AcTETA and N1,N8-diacetyltriethylenetetramine in an acidified high-performance liquid chromatography sample matrix. The complex metabolism of TETA together with the intramolecular N-acetyl migration may explain the huge individual variations in the acetylation rate of TETA reported earlier. PMID:21878558

  6. Differential expression of carnosine, homocarnosine and N-acetyl-L-histidine hydrolytic activities in cultured rat macroglial cells.

    PubMed

    Baslow, M H; Suckow, R F; Berg, M J; Marks, N; Saito, M; Bhakoo, K K

    2001-12-01

    N-acetyl-L-histidine (NAH) and N-acetyl-L-aspartate (NAA) are representatives of two series of substances that are synthesized by neurons and other cells in the vertebrate central nervous system (CNS). Histidine containing homologs of NAH are beta-alanyl-L-histidine or carnosine (Carn) and gamma-aminobutyrl-L-histidine or homocarnosine (Hcarn). A homolog of NAA is N-acetylaspartylglutamate (NAAG). These substances belong to a unique group of osmolytes in that they are synthesized in cells that may not to be able to hydrolyze them, and are released in a regulated fashion to a second compartment where they can be rapidly hydrolyzed. In this investigation, the catabolic activities for NAH, Carn, and Hcarn in cultured macroglial cells and neurons have been measured, and the second compartment for NAH and Hcarn has been identified only with astrocytes. In addition, oligodendrocytes can only hydrolyze Carn, although Carn can also be hydrolyzed by astrocytes. Thus, astrocytes express hydrolytic activity against all three substrates, but oligodendrocytes can only act on Carn. The cellular separation of these hydrolytic enzyme activities, and the possible nature of the enzymes involved are discussed.

  7. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  8. Effect of N-acetyl cysteine on Helicobacter pylori.

    PubMed

    Gurbuz, Ahmet Kemal; Ozel, A Melih; Ozturk, Ramazan; Yildirim, Sukru; Yazgan, Yusuf; Demirturk, Levent

    2005-11-01

    Use of mucolytic agents that result in reduced mucous viscosity of the gastric mucous has been suggested to have an additive effect in curing Helicobacter pylori infection. Seventy Hpylori-positive patients were given either eradication treatment consisting of 500 mg clarithromycin bid and 30 mg lansoprazole bid for 10 days plus 10 mL (400 mg) N-acetyl cysteine (NAC) liquid tid (AC group) or eradication treatment only (control group). The results were compared 1 month after the completion of the treatment. Fifty-eight patients were available for statistical analysis. Of the 28 patients in the AC group, 14 (50.0%) eradicated the infection after treatment, whereas only 7 of 30 (23.3%) patients in the control group had negative results. The difference between the AC group and the control group was statistically significant (P = 0.034). In both groups, there was no difference in the number of smokers and in the eradication rates between smokers and nonsmokers. Eradication treatment with or without NAC caused no significant side effects in either group. Our findings suggest that NAC has an additive effect on the eradication rates of H pylori obtained with dual therapy with lansoprazole and clarithromycin. NAC does not have any known activity against H pylori, but it may improve the delivery of antibiotics at the site of infection due to its ability to reduce the thickness of the mucus.

  9. N-acetyl cysteine therapy in acute viral hepatitis

    PubMed Central

    Gunduz, Huseyin; Karabay, Oguz; Tamer, Ali; Özaras, Resat; Mert, Ali; Tabak, Ömer Fehmi

    2003-01-01

    AIM: To investigate the effect of N-acetyl cysteine (NAC) on acute viral hepatitis (AVH). METHODS: We administered 200 mg oral NAC three times daily (600 mg/day) to the study group and placebo capsules to the control group. All patients were hospitalized and diagnosed as AVH. Blood total and direct bilirubin, ALT, AST, alkaline phosphatese, albumin and globulin levels of each patient were measured twice weekly until total bilirubin level dropped under 2 mg/dl, ALT level under 100 U/L, follow up was continued and then the patients were discharged. RESULTS: A total of 41(13 female and 28 male) AVH patients were included in our study. The period for normalization of ALT and total bilirubin in the study group was 19.7 ± 6.9 days and 13.7 ± 8.5 days respectively. In the control group it was 20.4 ± 6.5 days and 16.9 ± 7.8 days respectively (P > 0.05). CONCLUSION: NAC administration effected neither the time necessary for normalization of ALT and total bilirubin values nor duration of hospitalization, so we could not suggest NAC for the treatment of icteric AVH cases. However, our results have shown that this drug is not harmful to patients with AVH. PMID:14669316

  10. Effects of N-acetyl-cysteine and N-acetyl-cysteine-amide supplementation on in vitro matured porcine oocytes.

    PubMed

    Whitaker, B D; Knight, J W

    2010-10-01

    This study was conducted to evaluate the effects of different concentrations of the antioxidant N-acetyl-cysteine (NAC) supplemented to the maturation medium on porcine embryo development. Concentrations of NAC and its synthetic derivative, NAC-amide (NACA) were evaluated for effects on nuclear maturation, fertilization success and embryo development. Concentrations of NAC (0, 0.5, 1.0, 1.5, 2.0, 2.5 and 5.0 mm) were supplemented to maturing oocytes, and embryo development was analysed at 48 and 144 h post-fertilization. There were no differences among cleavage rates for any of the treatment groups. Blastocyst formation for 1.5 mm NAC (56.5 ± 9.2%) was higher (p < 0.05) than all other supplementations. There were no differences in nuclear maturation or fertilization or in cleavage rates when comparing 1.5 mm NAC and 1.5 mm NACA supplementation to the control. Blastocyst formation for 1.5 mm NAC (44.4 ± 4.7%) and 1.5 mm NACA (46.2 ± 3.4%) supplementation were higher (p < 0.05) than the control (32.1 ± 6.2%) oocytes. These results indicate that supplementing 1.5 mm of NAC or NACA to the oocyte maturation medium increased the percentage of viable embryos reaching the blastocyst stage of development. © 2009 Blackwell Verlag GmbH.

  11. N-Acetyl cysteine and erdosteine treatment in acetaminophen-induced liver damage.

    PubMed

    Saritas, Ayhan; Kandis, Hayati; Baltaci, Davut; Yildirim, Umran; Kaya, Halil; Karakus, Ali; Colakoglu, Serdar; Memisogullari, Ramazan; Kara, Ismail Hamdi

    2014-08-01

    This study is aimed to investigate the efficacy of erdosteine usage in acetaminophen-induced liver damage and to compare it with N-acetyl cysteine (NAC) in the treatment and prevention of liver toxicity due to overdose of acetaminophen. The rats were separated into the following six groups of seven rats each: control group; acetaminophen (1 g/kg, orally); acetaminophen (1 g/kg, orally) + erdosteine (150 mg/kg/day, orally); acetaminophen (1 g/kg, orally) + NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); erdosteine (150 mg/kg/kg, orally), subsequently. In all the groups, potential liver injuries were evaluated using biochemical and hematological analyses, oxidant-antioxidant parameters and histopathological parameters. In acetaminophen-treated group, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total oxidant status (TOS) in the blood, prothrombin time (PT) and international normalized ratio (INR) were significantly increased when compared with controls. However, total antioxidant capacity (TAC) and glutathione (GSH) levels were decreased in group treated with acetaminophen, when compared with control group. Levels of AST, ALT and TOS, PT and INR were decreased in groups treated with NAC and erdosteine after acetaminophen administration, but the levels of TAC and GSH were increased. Histopathological improvements were observed in the groups treated with NAC and erdosteine after acetaminophen administration. The present study demonstrated that, in the prevention of liver damage induced by acetaminophen intoxication, an early treatment with a single dose of erdosteine was beneficial instead of NAC administration. © The Author(s) 2012.

  12. Evaluation of the inhibitory effect of N-acetyl-L-cysteine on Babesia and Theileria parasites.

    PubMed

    Rizk, Mohamed Abdo; El-Sayed, Shimaa Abd El-Salam; AbouLaila, Mahmoud; Yokoyama, Naoaki; Igarashi, Ikuo

    2017-08-01

    N-acetyl-L-cysteine is known to have antibacterial, antiviral, antimalarial, and antioxidant activities. Therefore, the in vitro inhibitory effect of this hit was evaluated in the present study on the growth of Babesia and Theileria parasites. The in vitro growth of Babesia bovis, Babesia bigemina, Babesia divergens, Theileria equi, and Babesia caballi that were tested was significantly inhibited (P < 0.05) by micromolar concentrations of N-acetyl-L-cysteine. The inhibitory effect of N-acetyl-L-cysteine was synergistically potentiated when used in combination with diminazene aceturate on B. bovis and B. caballi cultures. These results indicate that N-acetyl-L-cysteine might be used as a drug for the treatment of babesiosis, especially when used in combination with diminazene aceturate. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Identification of structurally diverse methanofuran coenzymes in methanococcales that are both N-formylated and N-acetylated.

    PubMed

    Allen, Kylie D; White, Robert H

    2014-10-07

    Methanofuran (MF) is a coenzyme necessary for the first step of methanogenesis from CO2. The well-characterized MF core structure is 4-[N-(γ-l-glutamyl-γ-l-glutamyl)-p-(β-aminoethyl)phenoxymethyl]-2-(aminomethyl)furan (APMF-γ-Glu2). Three different MF structures that differ on the basis of the composition of their side chains have been determined previously. Here, we use liquid chromatography coupled with high-resolution mass spectrometry and a variety of biochemical methods to deduce the unique structures of MFs present in four different methanogens in the order Methanococcales. This is the first detailed characterization of the MF occurring in methanogens of this order. MF in each of these organisms contains the expected APMF-γ-Glu2; however, the composition of the side chain is different from that of the previously described MF structures. In Methanocaldococcus jannaschii, additional γ-linked glutamates that range from 7 to 12 residues are present. The MF coenzymes in Methanococcus maripaludis, Methanococcus vannielii, and Methanothermococcus okinawensis also have additional glutamate residues but interestingly also contain a completely different chemical moiety in the middle of the side chain that we have identified as N-(3-carboxy-2- or 3-hydroxy-1-oxopropyl)-l-aspartic acid. This addition results in the terminal γ-linked glutamates being incorporated in the opposite orientation. In addition to these nonacylated MF coenzymes, we also identified the corresponding N-formyl-MF and, surprisingly, N-acetyl-MF derivatives. N-Acetyl-MF has never been observed or implied to be functioning in nature and may represent a new route for acetate formation in methanogens.

  14. Determination of DNA damage in experimental liver intoxication and role of N-acetyl cysteine.

    PubMed

    Aksit, Hasan; Bildik, Aysegül

    2014-11-01

    The present study aimed at detecting DNA damage and fragmentation as well as histone acetylation depending on oxidative stress caused by CCl4 intoxication. Also, the protective role of N-acetyl cysteine, a precursor for GSH, in DNA damage is investigated. Sixty rats were used in this study. In order to induce liver toxicity, CCl4 in was dissolved in olive oil (1/1) and injected intraperitoneally as a single dose (2 ml/kg). N-acetyl cysteine application (intraperitoneal, 50 mg/kg/day) was started 3 days prior to CCl4 injection and continued during the experimental period. Control groups were given olive oil and N-acetyl cysteine. After 6 and 72 h of CCl4 injection, blood and liver tissue were taken under ether anesthesia. Nuclear extracts were prepared from liver. Changes in serum AST and ALT activities as well as MDA, TAS, and TOS levels showed that CCl4 caused lipid peroxidation and liver damage. However, lipid peroxidation and liver damage were reduced in the N-acetyl cysteine group. Increased levels in 8-hydroxy-2-deoxy guanosine and histone acetyltransferase activities, decreased histone deacetylase activities, and DNA breakage detected in nuclear extracts showed that CCl4 intoxication induces oxidative stress and apoptosis in rat liver. The results of the present study indicate that N-acetyl cysteine has a protective effect on CCl4-induced DNA damage.

  15. Patterns of N-acetyl-beta-glucosaminidase isoenzymes in the epidermis and hepatopancreas and induction of N-acetyl-beta-glucosaminidase activity by 20-hydroxyecdysone in the fiddler crab, Uca pugilator.

    PubMed

    Zou, E; Fingerman, M

    1999-11-01

    A new staining method for detection of N-acetyl-beta-glucosaminidase on denaturing SDS polyacrylamide gels was developed. The isoenzyme pattern of N-acetyl-beta-glucosaminidase in the epidermis of the fiddler crab, Uca pugilator, is different from that in the hepatopancreas. Two isoforms of N-acetyl-beta-glucosaminidase, with molecular weights of 89 and 45.6 kDa, are present in the hepatopancreas while there is only one form of N-acetyl-beta-glucosaminidase, 89 kDa, in the epidermis. No sexual dimorphism was found in these patterns of N-acetyl-beta-glucosaminidase isoenzymes. The characteristic isoenzyme patterns in the epidermis and hepatopancreas occurred consistently throughout the molting cycle. Injections of the molting hormone, 20-hydroxyecdysone, at 25 microg/g live weight, into crabs in premolt substage D1, significantly increased N-acetyl-beta-glucosaminidase activity in the epidermis by 86%. Since only one form of N-acetyl-beta-glucosaminidase, 89 kDa, is present in the epidermis, the elevation in epidermal enzymatic activity after 20-hydroxyecdysone administration is entirely accounted for by this N-acetyl-beta-glucosaminidase isoenzyme. The results reported herein are the first direct evidence that in a crustacean N-acetyl-beta-glucosaminidase activity is regulated by the steroid molting hormone.

  16. Conformational studies of bacterial peptidoglycan: structure and stereochemistry of N-acetyl-β- D-glucosamine and N-acetyl-β- D-muramic acid

    NASA Astrophysics Data System (ADS)

    Yadav, P. N. S.; Rai, D. K.; Yadav, J. S.

    1989-03-01

    The energies of various conformations of N-acetyl-β- D-glucosamine (NAG) and its 3-O- D-lactic acid derivative N-acetyl-β- D-muramic acid (NAM) have been calculated by geometry optimization using the molecular mechanics program MM2. The geometries of these systems have been analyzed in the light of ring torsion, bond lengths, bond angles and conformational states of side groups of the pyranosyl ring and compared with available experimental data of similar pyranose derivatives. The present study indicates the presence of hydrogen bonds to stabilize the side group conformations. Discrepancies with experimental data that are seen in a few cases are ascribed to the nature of the side groups and their geometry.

  17. Structural basis for the De-N-acetylation of Poly-β-1,6-N-acetyl-D-glucosamine in Gram-positive bacteria.

    PubMed

    Little, Dustin J; Bamford, Natalie C; Pokrovskaya, Varvara; Robinson, Howard; Nitz, Mark; Howell, P Lynne

    2014-12-26

    Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In staphylococci, partial de-N-acetylation of the exopolysaccharide poly-β-1,6-N-acetyl-d-glucosamine (PNAG) by the extracellular protein IcaB is required for biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of IcaB from Ammonifex degensii (IcaBAd) has been determined to 1.7 Å resolution. The structure of IcaBAd reveals a (β/α)7 barrel common to the family four carbohydrate esterases (CE4s) with the canonical motifs circularly permuted. The metal dependence of IcaBAd is similar to most CE4s showing the maximum rates of de-N-acetylation with Ni(2+), Co(2+), and Zn(2+). From docking studies with β-1,6-GlcNAc oligomers and structural comparison to PgaB from Escherichia coli, the Gram-negative homologue of IcaB, we identify Arg-45, Tyr-67, and Trp-180 as key residues for PNAG binding during catalysis. The absence of these residues in PgaB provides a rationale for the requirement of a C-terminal domain for efficient deacetylation of PNAG in Gram-negative species. Mutational analysis of conserved active site residues suggests that IcaB uses an altered catalytic mechanism in comparison to other characterized CE4 members. Furthermore, we identified a conserved surface-exposed hydrophobic loop found only in Gram-positive homologues of IcaB. Our data suggest that this loop is required for membrane association and likely anchors IcaB to the membrane during polysaccharide biosynthesis. The work presented herein will help guide the design of IcaB inhibitors to combat biofilm formation by staphylococci.

  18. Catalytic Depolymerization of Chitin with Retention of N-Acetyl Group.

    PubMed

    Yabushita, Mizuho; Kobayashi, Hirokazu; Kuroki, Kyoichi; Ito, Shogo; Fukuoka, Atsushi

    2015-11-01

    Chitin, a polymer of N-acetylglucosamine units with β-1,4-glycosidic linkages, is the most abundant marine biomass. Chitin monomers containing N-acetyl groups are useful precursors to various fine chemicals and medicines. However, the selective conversion of robust chitin to N-acetylated monomers currently requires a large excess of acid or a long reaction time, which limits its application. We demonstrate a fast catalytic transformation of chitin to monomers with retention of N-acetyl groups by combining mechanochemistry and homogeneous catalysis. Mechanical-force-assisted depolymerization of chitin with a catalytic amount of H2SO4 gave soluble short-chain oligomers. Subsequent hydrolysis of the ball-milled sample provided N-acetylglucosamine in 53% yield, and methanolysis afforded 1-O-methyl-N-acetylglucosamine in yields of up to 70%. Our process can greatly reduce the use of acid compared to the conventional process.

  19. Rate assay of N-acetyl-beta-D-hexosaminidase with 4-nitrophenyl N-acetyl-beta-D-glucosaminide as an artificial substrate.

    PubMed

    Shibata, H; Yagi, T

    1996-07-15

    A rapid and accurate rate assay method for N-acetyl-beta-D-hexosaminidase (EC 3.2.1.52, also known as N-acetyl-beta-D-glucosaminidase, or NAGase) using 4-nitrophenyl N-acetyl-beta-D-glucosaminide (NP-GlcNAc) as an artificial substrate was developed using diethylaminoethyl-alpha-cyclodextrin (DEn-CD, where n is the number of diethylaminoethyl groups introduced to alpha-cyclodextrin), as an additive to ionize 4-nitrophenol to yellow-colored 4-nitrophenoxide at pH near 5, where the enzyme acts optimally. A possible recipe for the rate assay of NAGase is as follows. Prepare a stock solution containing 4.8 mmol/l NP-GlcNAc and 1% DEn-CD (n is preferably near 17) in 0.1 mol/l glycolate buffer, pH 5.50. Introduce the stock solution and a properly diluted sample (urine or other body fluid) to a reaction cell placed in a spectrophotometer at a ratio of 1:1, and monitor the absorbance at 400 or 420 nm. The reaction rate (enzymatic activity) can be conveniently read directly from calibration plots prepared for a given lot of DEn-CD sample, or can be calculated from the rate of the absorbance increase, ionization degree of 4-nitrophenol at pH 5.50, and the millimolar absorbance coefficient of 4-nitrophenoxide in the presence of 0.5% DEn-CD.

  20. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, a Review of Effectiveness in Reducing HIV Progression

    PubMed Central

    Hummelen, Ruben; Hemsworth, Jaimie; Reid, Gregor

    2010-01-01

    Low serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics, and prebiotics has considerable potential, but the evidence needs to be further substantiated. Vitamin A, iron, and zinc have been associated with adverse effects and caution is warranted for their use. PMID:22254046

  1. First observation of N-acetyl leucine and N-acetyl isoleucine in diabetic patient hair and quantitative analysis by UPLC-ESI-MS/MS.

    PubMed

    Min, Jun Zhe; Tomiyasu, Yuki; Morotomi, Takashi; Jiang, Ying-Zi; Li, Gao; Shi, Qing; Yu, Hai-Fu; Inoue, Koichi; Todoroki, Kenichiro; Toyo'oka, Toshimasa

    2015-04-15

    Type 2 diabetes patients (DP) have significantly higher plasma levels of valine, leucine, isoleucine and alanine than the controls. Specific amino acids may acutely and chronically regulate insulin secretion from the pancreatic β-cells. We recently identified a metabolic signature of N-acetyl leucine (Ac-Leu) that strongly predicts diabetes development in mice hair. The Ac-Leu appears to be a potential biomarker candidate related to diabetes. However, the determination of Ac-Leu in human hair has not been reported. We measured the Ac-Leu, and its structure is similar to N-acetyl isoleucine (Ac-Ile) in human hair by ultra-performance liquid chromatography (UPLC) with electrospray ionization tandem mass spectrometry (ESI-MS/MS). The developed method was applied to the determination of Ac-Leu and Ac-Ile in the hair of healthy volunteers (HV) and DP. Ac-Leu, Ac-Ile and N-acetyl norleucine (Ac-Nle, IS) were extracted from human hair samples by a micropulverized extraction procedure, then separated on a C18 column by isocratic elution of acetonitrile-0.1% formic acid in water:0.1% formic acid (14:86, vol./vol.). MRM using the fragmentation transitions of m/z 174.1→86.1 in the positive ESI mode was performed to quantify the N-acetyl leucine, N-acetyl isoleucine and IS. Ac-Leu, Ac-Ile and Ac-Nle in the human hair samples were completely separated by isocratic elution of a 5.0 min duration wash program using a reversed-phase column, and sensitively detected by LC-MS/MS in the ESI(+) MRM mode. The amounts of Ac-Leu and Ac-Ile in the hairs of HV and DP were determined. When comparing the concentrations between DP and those from HV, a statistically significant correlation was observed for the Ac-Leu (p<0.001) and Ac-Ile (p<0.01). The proposed method is useful for the determination of Ac-Leu and Ac-Ile in the hairs of DP and HV. Human hair may serve as a noninvasive biosample for the diagnosis of diabetes. Crown Copyright © 2015. Published by Elsevier B.V. All rights

  2. Inhibition of the adenine nucleotide translocator by N-acetyl perfluorooctane sulfonamides in vitro

    SciTech Connect

    O'Brien, Timothy M. Oliveira, Paulo J.; Wallace, Kendall B.

    2008-03-01

    N-alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anti-corrosion agents, among many other commercial applications. The global distribution and environmental persistence of these compounds has generated considerable interest regarding potential toxic effects. We have previously reported that perfluorooctanesulfonamidoacetate (FOSAA) and N-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA) induce the mitochondrial permeability transition (MPT) in vitro. In this study we tested the hypothesis that FOSAA and N-EtFOSAA interact with the adenine nucleotide translocator (ANT) resulting in a functional inhibition of the translocator and induction of the MPT. Respiration and membrane potential of freshly isolated liver mitochondria from Sprague-Dawley rats were measured using an oxygen electrode and a tetraphenylphosphonium-selective (TPP{sup +}) electrode, respectively. Mitochondrial swelling was measured spectrophotometrically. The ANT ligands bongkregkic acid (BKA) and carboxyatractyloside (cATR) inhibited uncoupling of mitochondrial respiration caused by 10 {mu}M N-EtFOSAA, 40 {mu}M FOSAA, and the positive control 8 {mu}M oleic acid. ADP-stimulated respiration and depolarization of mitochondrial membrane potential were inhibited by cATR, FOSAA, N-EtFOSAA, and oleic acid, but not by FCCP. BKA inhibited calcium-dependent mitochondrial swelling induced by FOSAA, N-EtFOSAA, and oleic acid. Seventy-five micromolar ADP also inhibited swelling induced by the test compounds, but cATR induced swelling was not inhibited by ADP. Results of this investigation indicate that N-acetyl perfluorooctane sulfonamides interact directly with the ANT to inhibit ADP translocation and induce the MPT, one or both of which may account for the metabolic dysfunction observed in vivo.

  3. Poly-N-acetyl glucosamine-mediated red blood cell interactions.

    PubMed

    Thatte, Hemant S; Zagarins, Sofija E; Amiji, Mansoor; Khuri, Shukri F

    2004-07-01

    Investigations were performed to assess the effect of poly-N-acetyl glucosamine (p-GlcNAc) fiber slurry-mediated hemostasis by interactions with red blood cells. Red blood cell aggregation studies were performed using test material-coated microscope slides and multiphoton microscopic measurements. Enzymatic removal of red blood cell surface proteins was achieved using trypsin and neuraminidase treatment. Zeta-potential measurements (surface charge) were performed. Red blood cells interact directly with poly-N-acetyl glucosamine polymers through ionic interactions and cell-surface proteins. The effective concentration of poly-N-acetyl glucosamine fiber material for 50% red blood cell aggregation was 0.28 mg/mL. The p-GlcNAc beta-configuration fibers and an alpha-configuration structural modification of the fibers both produced maximal responses because of their zeta-potentials, whereas other chemically modified p-GlcNAcs and chitosans were ineffective. Poly-N-acetyl glucosamine-induced red blood cell aggregation is mediated by interactions with red blood cell surface charges.

  4. Identification of the major endogenous leukotriene metabolite in the bile of rats as N-acetyl leukotriene E4

    SciTech Connect

    Hagmann, W.; Denzlinger, C.; Rapp, S.; Weckbecker, G.; Keppler, D.

    1986-02-01

    Mercapturic acid formation, an established pathway in the detoxication of xenobiotics, is demonstrated for cysteinyl leukotrienes generated in rats in vivo after endotoxin treatment. The mercapturate N-acetyl-leukotriene E4 (N-acetyl-LTE4) represented a major metabolite eliminated into bile after injection of (/sup 3/H)LTC4 as shown by cochromatography with synthetic N-acetyl-LTE4 in four different HPLC solvent systems. The identity of endogenous N-acetyl-LTE4 elicited by endotoxin in vivo was additionally verified by enzymatic deacetylation followed by chemical N-acetylation. The deacetylation was catalyzed by penicillin amidase. Endogenous cysteinyl leukotrienes were quantified by radioimmunoassay after HPLC separation. A N-acetyl-LTE4 concentration of 80 nmol/l was determined in bile collected between 30 and 60 min after endotoxin injection. Under this condition, other cysteinyl leukotrienes detected in bile by radioimmunoassay amounted to less than 5% of N-acetyl-LTE4. The mercapturic acid pathway, leading from the glutathione conjugate LTC4 to N-acetyl-LTE4, thus plays an important role in the deactivation and elimination of these potent endogenous mediators.

  5. Identification of the major endogenous leukotriene metabolite in the bile of rats as N-acetyl leukotriene E4.

    PubMed

    Hagmann, W; Denzlinger, C; Rapp, S; Weckbecker, G; Keppler, D

    1986-02-01

    Mercapturic acid formation, an established pathway in the detoxication of xenobiotics, is demonstrated for cysteinyl leukotrienes generated in rats in vivo after endotoxin treatment. The mercapturate N-acetyl-leukotriene E4 (N-acetyl-LTE4) represented a major metabolite eliminated into bile after injection of [3H]LTC4 as shown by cochromatography with synthetic N-acetyl-LTE4 in four different HPLC solvent systems. The identity of endogenous N-acetyl-LTE4 elicited by endotoxin in vivo was additionally verified by enzymatic deacetylation followed by chemical N-acetylation. The deacetylation was catalyzed by penicillin amidase. Endogenous cysteinyl leukotrienes were quantified by radioimmunoassay after HPLC separation. A N-acetyl-LTE4 concentration of 80 nmol/l was determined in bile collected between 30 and 60 min after endotoxin injection. Under this condition, other cysteinyl leukotrienes detected in bile by radioimmunoassay amounted to less than 5% of N-acetyl-LTE4. The mercapturic acid pathway, leading from the glutathione conjugate LTC4 to N-acetyl-LTE4, thus plays an important role in the deactivation and elimination of these potent endogenous mediators.

  6. N-acetylation of three aromatic amine hair dye precursor molecules eliminates their genotoxic potential.

    PubMed

    Zeller, Andreas; Pfuhler, Stefan

    2014-01-01

    N-acetylation has been described as a detoxification reaction for aromatic amines; however, there is only limited data available showing that this metabolic conversion step changes their genotoxicity potential. To extend this database, three aromatic amines, all widely used as precursors in oxidative hair dye formulations, were chosen for this study: p-phenylenediamine (PPD), 2,5-diaminotoluene (DAT) and 4-amino-2-hydroxytoluene (AHT). Aiming at a deeper mechanistic understanding of the interplay between activation and detoxification for this chemical class, we compared the genotoxicity profiles of the parent compounds with those of their N-acetylated metabolites. While PPD, DAT and AHT all show genotoxic potential in vitro, their N-acetylated metabolites completely lack genotoxic potential as shown in the Salmonella typhimurium reversion assay, micronucleus test with cultured human lymphocytes (AHT), chromosome aberration assay with V79 cells (DAT) and Comet assay performed with V79 cells. For the bifunctional aromatic amines studied (PPD and DAT), monoacetylation was sufficient to completely abolish their genotoxic potential. Detoxification through N-acetylation was further confirmed by comparing PPD, DAT and AHT in the Comet assay using standard V79 cells (N-acetyltransferase (NAT) deficient) and two NAT-proficient cell lines,V79NAT1*4 and HaCaT (human keratinocytes). Here we observed a clear shift of dose-response curves towards decreased genotoxicity of the parent aromatic amines in the NAT-proficient cells. These findings suggest that genotoxic effects will only be found at concentrations where the N-acetylation (detoxifying) capacity of the cells is overwhelmed, indicating that a 'first-pass' effect in skin could be taken into account for risk assessment of these topically applied aromatic amines. The findings also indicate that the use of liver S-9 preparations, which generally underestimate Phase II reactions, contributes to the generation of irrelevant

  7. Acetaminophen analog N-acetyl-m-aminophenol, but not its reactive metabolite, N-acetyl-p-benzoquinone imine induces CYP3A activity via inhibition of protein degradation.

    PubMed

    Santoh, Masataka; Sanoh, Seigo; Ohtsuki, Yuya; Ejiri, Yoko; Kotake, Yaichiro; Ohta, Shigeru

    2017-05-06

    Cytochrome P450 (CYP) 3A subfamily members are known to metabolize various types of drugs, highlighting the importance of understanding drug-drug interactions (DDI) depending on CYP3A induction or inhibition. While transcriptional regulation of CYP3A members is widely understood, post-translational regulation needs to be elucidated. We previously reported that acetaminophen (APAP) induces CYP3A activity via inhibition of protein degradation and proposed a novel DDI concept. N-Acetyl-p-benzoquinone imine (NAPQI), the reactive metabolite of APAP formed by CYP, is known to cause adverse events related to depletion of intracellular reduced glutathione (GSH). We aimed to inspect whether NAPQI rather than APAP itself could cause the inhibitory effects on protein degradation. We found that N-acetyl-l-cysteine, the precursor of GSH, and 1-aminobenzotriazole, a nonselective CYP inhibitor, had no effect on CYP3A1/23 protein levels affected by APAP. Thus, we used APAP analogs to test CYP3A1/23 mRNA levels, protein levels, and CYP3A activity. We found N-acetyl-m-aminophenol (AMAP), a regioisomer of APAP, has the same inhibitory effects of CYP3A1/23 protein degradation, while p-acetamidobenzoic acid (PAcBA), a carboxy-substituted form of APAP, shows no inhibitory effects. AMAP and PAcBA cannot be oxidized to quinone imine forms such as NAPQI, so the inhibitory effects could depend on the specific chemical structure of APAP. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The disturbance of oxidative phosphorylation by N-acetoxy-N-acetyl-2-aminofluorene, a model ultimate carcinogen.

    PubMed

    Hadler, H I; Demetriou, J M

    1975-10-01

    Currently N-acetoxy-N-acetyl-2-aminofluorene is favored by many investigators to be a model of the ultimate electrophilic carcinogenic agent derived metabolically from the carcinogen N-acetyl-2-aminofluprene. The model induced in vitro a delayed ATP energized increase in mitochondrial volume as indicated by the decrease in absorbancy at 520 nm. The ATP energized decrease in absorbancy was inhibited by rutamycin, 2,4-dinitrophenol and a high level of antimycin known to induce ATPase activity. The known to inhibit respiration without inducing ATPase activity. Malate or potassium ion did not affect the phenomenon, however, sulfate ion which has been implicated in liver carcinogenesis shortened the induction period. Showdomycin stimulated the phenomenon. N-Acetoxy-N-acetyl-2-aminofluorene interacts with the machinery of oxidative phosphorylation. N-Acetoxy-N-acetyl-2-aminofluorene was enzymically converted by the mitochondria to N-hydroxy-N-acetyl-2-aminofluorene. These findings extend the experimental confluence of oxidative phosphorylation with carcinogenesis.

  9. Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans

    PubMed Central

    Oh, Seung-Il; Park, Jin-Kook; Park, Sang-Kyu

    2015-01-01

    OBJECTIVE: This study was performed to determine the effect of N-acetyl-L-cysteine, a modified sulfur-containing amino acid that acts as a strong cellular antioxidant, on the response to environmental stressors and on aging in C. elegans. METHOD: The survival of worms under oxidative stress conditions induced by paraquat was evaluated with and without in vivo N-acetyl-L-cysteine treatment. The effect of N-acetyl-L-cysteine on the response to other environmental stressors, including heat stress and ultraviolet irradiation (UV), was also monitored. To investigate the effect on aging, we examined changes in lifespan, fertility, and expression of age-related biomarkers in C. elegans after N-acetyl-L-cysteine treatment. RESULTS: Dietary N-acetyl-L-cysteine supplementation significantly increased resistance to oxidative stress, heat stress, and UV irradiation in C. elegans. In addition, N-acetyl-L-cysteine supplementation significantly extended both the mean and maximum lifespan of C. elegans. The mean lifespan was extended by up to 30.5% with 5 mM N-acetyl-L-cysteine treatment, and the maximum lifespan was increased by 8 days. N-acetyl-L-cysteine supplementation also increased the total number of progeny produced and extended the gravid period of C. elegans. The green fluorescent protein reporter assay revealed that expression of the stress-responsive genes, sod-3 and hsp-16.2, increased significantly following N-acetyl-L-cysteine treatment. CONCLUSION: N-acetyl-L-cysteine supplementation confers a longevity phenotype in C. elegans, possibly through increased resistance to environmental stressors. PMID:26039957

  10. Vaccines containing de-N-acetyl sialic acid elicit antibodies protective against Neisseria meningitidis group B and C1

    PubMed Central

    Moe, Gregory R.; Bhandari, Tamara S.; Flitter, Becca A.

    2009-01-01

    Murine monoclonal antibodies (mAbs) that were produced by immunization with a vaccine containing the N-propionyl derivative of Neisseria meningitidis group B (MenB) capsular polysaccharide (NPr MBPS) mediate protective responses against MenB but were not reactive with unmodified MBPS or chemically identical human polysialic acid (PSA). Recently, we showed that some of the mAbs were reactive with MBPS derivatives that contain de-N-acetyl sialic acid residues (Moe et al. 2005, Infect Immun 73:2123–2128). In this study we evaluated the immunogenicity of de-N-acetyl sialic acid-containing derivatives of PSA (de-N-acetyl PSA) in mice. Four de-N-acetyl PSA antigens were prepared and conjugated to tetanus toxoid, including completely de-N-acetylated PSA. All of the vaccines elicited anti-de-N-acetyl PSA responses (titers ≥1:10,000) but only vaccines enriched for non-reducing end de-N-acetyl residues by treatment with exoneuraminidase or complete de-N-acetylation elicited high titers against the homologous antigen. Also, non-reducing end de-N-acetyl residue-enriched vaccines elicited IgM and IgG antibodies of all subclasses that could bind to MenB. The results suggest that the zwitterionic characteristic of neuraminic acid, particularly at the non-reducing end may be important for processing and presentation mechanisms that stimulate T cells. Antibodies elicited by all four vaccines were able to activate deposition of human complement proteins and passively protect against challenge by MenB in the infant rat model of meningococcal bacteremia. Some vaccine antisera mediated bactericidal activity against a MenC strain with human complement. Thus, de-N-acetyl PSA antigens are immunogenic and elicit antibodies that can be protective against MenB and C strains. PMID:19414816

  11. Production of N-Acetyl-d-glucosamine from Mycelial Waste by a Combination of Bacterial Chitinases and an Insect N-Acetyl-d-glucosaminidase.

    PubMed

    Zhu, Weixing; Wang, Di; Liu, Tian; Yang, Qing

    2016-09-07

    N-Acetyl-d-glucosamine (GlcNAc) has great potential to be used as a food additive and medicine. The enzymatic degradation of chitin-containing biomass for producing GlcNAc is an eco-friendly approach but suffers from a high cost. The economical efficiency can be improved by both optimizing the member and ratio of the chitinolytic enzymes and using new inexpensive substrates. To address this, a novel combination of bacterial and insect chitinolytic enzymes was developed in this study to efficiently produce GlcNAc from the mycelia of Asperillus niger, a fermentation waste. This enzyme combination contained three bacterial chitinases (chitinase A from Serratia marcescens (SmChiA), SmChiB, SmChiC) and one insect N-acetyl-d-glucosaminidase from Ostrinia furnacalis (OfHex1) in a ratio of 39.1% of SmChiA, 26.7% of SmChiB, 32.9% of SmChiC, and 1.3% of OfHex1. A yield of 6.3 mM (1.4 mg/mL) GlcNAc with a purity of 95% can be obtained from 10 mg/mL mycelial powder in 24 h. The enzyme combination reported here exhibited 5.8-fold higher hydrolytic activity over the commercial chitinase preparation derived from Streptomyces griseus.

  12. Carfilzomib-related acute kidney injury may be prevented by N-acetyl-L-cysteine.

    PubMed

    Wanchoo, Rimda; Khan, Seyyar; Kolitz, Jonathan E; Jhaveri, Kenar D

    2015-08-01

    Carfilzomib is a second-generation epoxyketone proteasome inhibitor that is approved for treatment of relapsed and refractory multiple myeloma. Phase 2 trials have reported that 25% of treated patients have renal adverse effects. Pre-renal/vasoconstriction-related insult from this chemotherapy agent has been documented. We describe a case of a 78-year-old man with refractory multiple myeloma with acute kidney injury associated with carfilzomib treatment. We show that use of N-acetyl-l-cysteine in our patient partially mitigated the renal injury upon re-challenge. This case report hypothesizes that acute renal injury from carfilzomib is caused by vasoconstriction of the renal vessels, which may be prevented by N-acetyl-l-cysteine.

  13. A rapid test for chitinase activity that uses 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide.

    PubMed Central

    O'Brien, M; Colwell, R R

    1987-01-01

    A total of 101 strains of bacteria from environmental and clinical sources, most of which were gram negative, were tested for chitobiase activity by using a filter paper spot test with 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide as the substrate. The results were compared with those obtained by a conventional plate method for chitinase activity by using colloidal chitin as the substrate. There was excellent agreement in the results for both methods. The filter paper spot test with 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide has the advantages of being rapid, simple to perform, and inexpensive. This method should be adaptable to a wider range of microorganisms, particularly those with unusual growth requirements. PMID:3662513

  14. PURIFICATION AND PROPERTIES OF N-ACETYL-d-GLUCOSAMINE KINASE FROM STREPTOCOCCUS PYOGENES

    PubMed Central

    Zeleznick, L. D.; Hankin, H.; Boltralik, J. J.; Heymann, H.; Barkulis, S. S.

    1964-01-01

    Zeleznick, L. D. (CIBA Pharmaceutical Co., Summit, N.J.), H. Hankin, J. J. Boltralik, H. Heymann, and S. S. Barkulis. Purification and properties of N-acetyl-d-glucosamine kinase from Streptococcus pyogenes. J. Bacteriol. 88:1288–1295. 1964.—A kinase from Streptococcus pyogenes which catalyzes adenosine triphosphate-dependent phosphorylation of d-glucose and N-acetyl-d-glucosamine has been purified 1,500-fold. The ratio of the enzymatic activity on both substrates remained constant throughout the fractionation. Similarity in heat stability, p-hydroxymercuribenzoate inhibition, protection by either carbohydrate, and lack of repression of enzymatic activity when the bacteria were grown exclusively on one of the two substrates supports the hypothesis that kinase activity is associated with one enzyme. PMID:14234783

  15. Conformations of N-acetyl-L-prolinamide by two-dimensional infrared spectroscopy.

    PubMed

    Sul, Soohwan; Karaiskaj, Denis; Jiang, Ying; Ge, Nien-Hui

    2006-10-12

    Femtosecond two-dimensional infrared (2D IR) spectroscopy has been applied to study the conformations of a model dipeptide, N-acetyl-L-prolinamide (AcProNH2) in deuterated chloroform (CDCl3). Spectral features in the amide-I and -II regions are obtained by rephasing (R), nonrephasing (NR), and reverse photon echo (RPE) pulse sequences with two polarization conditions. The 2D spectra obtained by the RPE and NR sequences with (0, 0, 0, 0) polarization reveal new spectral features associated with the multiple conformers of AcProNH2 that are difficult to discern using R sequence and linear-IR spectroscopy. The high resolving power of the RPE sequence comes from destructive interference between the positive and negative peaks of nearby vibrators, similar to the NR sequence. The RPE response functions that are useful for 2D spectral simulations are evaluated, including the effects of vibrational frequency correlations. The 2D spectra obtained with (45, -45, 90, 0) polarization exhibit clear cross-peak patterns in the off-diagonal region for the R and RPE sequences but in the diagonal region for the NR sequence. These patterns, free from strong diagonal contributions, are crucial for structure determination. DFT calculations, normal-mode analysis, Hessian matrix reconstruction, and vibrational exciton Hamiltonian diagonalization yield molecular parameters needed for quantitative simulations of 2D spectra: angles between transition dipoles, coupling constants, and off-diagonal anharmonicities of the amide-I and -II modes are obtained for solvated trans-C7 and cis structures and for gas-phase trans conformers in the region of phi = -120 degrees to 0 degrees and psi = -100 degrees to 180 degrees in the Ramachandran space. Systematic simulations based on a 4:1 population ratio of the solvated trans-C7 and cis structures reproduce well the 2D spectral features obtained at both polarization conditions. However, better agreement between the experimental and simulated cross

  16. N-acetyl Glucosamine Distribution and Mitochondrial Activity of Tumor Cell Exposed to Photodynamic Therapy.

    PubMed

    Pinto, G P; Lopes, K A R; Salles, N G; Pacheco-Soares, C

    2016-11-01

    The use of lectins can play an important role for tracking modification on cell surface components, since lectins can be easily complexed with radioisotopes, biotin or fluorescein, facilitating the evaluation of carbohydrates distribution in the cell and mitochondrial activity. The aim of this study was to evaluate photodynamic therapy effects on indirect distribution of N-acetyl-glucosamine terminal glycoproteins, in human laryngeal carcinoma HEp-2 cell line surface, using lectin wheat germ agglutinin (WGA) and on mitochondrial activity, for the same cell line, using MitoTracker. The photosensitizer Aluminum Phthalocyanine Tetrasulfonate (AlPcS4) was administrated at 10 μM/mL, followed by an incubation period for its accumulation in the tumor cells, which were irradiated with laser diode λ = 685 nm and energy density of 4.5 J/cm(2). Our results indicated that, after Photodynamic Therapy (PDT), it was observed N-acetyl glucosamine terminal glycoprotein expression and mitochondrial O2 production, compared to the control group. Based on these results, we suggest that PDT influences the O2 mitochondrial production and the presence of surface glycoproteins N-acetyl glucosamine terminals.

  17. [Activity of N-acetyl-β-hexosaminidase and its isoenzymes A and B in cancer].

    PubMed

    Choromańska, Barbara; Luto, Magdalena; Szajda, Sławomir Dariusz; Waszkiewicz, Napoleon; Kępka, Alina; Janica, Jacek; Ladny, Jerzy Robert; Dadan, Jacek; Myśliwiec, Piotr; Zwierz, Krzysztof

    2011-11-23

    There were approximately 93,060 deaths from cancers in Poland in 2008, and about 105,000 are predicted for the year 2025. Early detection of cancer is a major problem throughout the world, which is why many researchers are still looking for specific and sensitive markers of malignant tumors. Our work is a review of recent publications on activity of N-acetyl-β-D-hexosaminidase (HEX) and its isoenzymes A (HEX A) and B (HEX B) as potential markers of malignant tumors. HEX is the most active of the lysosomal exoglycosidases, taking part in degradation of glycoconjugates (glycoproteins, glycolipids, proteoglycans). HEX cleaves N-acetyl-D-glucosamine and N-acetyl-D-galactosamine from non-reducing ends of oligosaccharide chains of glycoproteins, glycolipids and glycosaminoglycans. The activity of HEX, and its isoenzymes A (HEX A) and B (HEX B), was determined by spectrophotometric and isoelectric focusing methods. There was a statistically significant increase in activity of HEX in tumors of the kidney, pancreas, thyroid, colon, ovary, brain, salivary gland, stomach and larynx, which suggests potential applicability of HEX and its isoenzymes in cancer diagnosis.

  18. N-acetyl-β-hexosaminidase in chronic tonsillitis and tonsillar hypertrophy.

    PubMed

    Zagor, Mariola; Minarowska, Alina; Knaś, Małgorzata; Krajewska, Katarzyna; Niemcunowicz-Janica, Anna; Marciniak, Justyna; Bierć, Marcin; Zaniewska, Agnieszka; Minarowski, Lukasz; Jackowska, Anna; Jackowski, Tomasz; Zwierz, Krzysztof; Szajda, Sławomir

    2013-01-01

    The concentration and specific activity of N-acetyl-β-hexosaminidase (HEX) in palatine tonsils with chronic tonsillitis and tonsillar hypertrophy give insight in tonsillar tissue remodeling and constitute a potential marker for diagnosis and treatment of chronic tonsillitis and tonsillar hypertrophy. Determining the concentration and specific activity of N-acetyl-β-hexosaminidase in palatine tonsils with hypertrophy and chronic tonsillitis. HEX activity was analyzed by the method of Marciniak et al. with p-nitrophenyl N-acetyl-β-glucosaminepyranoside as a substrate. The concentration and specific activity of HEX in palatine tonsils in patients with tonsillar hypertrophy and chronic tonsillitis both in childhood and adulthood significantly increase in comparison to healthy individuals. Our data demonstrate the presence of HEX in palatine tonsils and indicate on significant increase of its concentration and specific activity. Based on content and specific HEX activity we suggest that tonsils with hypertrophy and chronic tonsillitis should be treated as identical unit irrespectively of age. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  19. Protective Roles of N-acetyl Cysteine and/or Taurine against Sumatriptan-Induced Hepatotoxicity

    PubMed Central

    Khalili Fard, Javad; Hamzeiy, Hossein; Sattari, Mohammadreza; Eghbal, Mohammad Ali

    2016-01-01

    Purpose: Triptans are the drug category mostly prescribed for abortive treatment of migraine. Most recent cases of liver toxicity induced by triptans have been described, but the mechanisms of liver toxicity of these medications have not been clear. Methods: In the present study, we obtained LC50 using dose-response curve and investigated cell viability, free radical generation, lipid peroxide production, mitochondrial injury, lysosomal membrane damage and the cellular glutathione level as toxicity markers as well as the beneficial effects of taurine and/or N-acetyl cysteine in the sumatriptan-treated rat parenchymal hepatocytes using accelerated method of cytotoxicity mechanism screening. Results: It was revealed that liver toxicity induced by sumatriptan in in freshly isolated parenchymal hepatocytes is dose-dependent. Sumatriptan caused significant free radical generation followed by lipid peroxide formation, mitochondrial injury as well as lysosomal damage. Moreover, sumatriptan reduced cellular glutathione content. Taurine and N-acetyl cysteine were able to protect hepatocytes against sumatriptan-induced harmful effects. Conclusion: It is concluded that sumatriptan causes oxidative stress in hepatocytes and the decreased hepatocytes glutathione has a key role in the sumatriptan-induced harmful effects. Also, N-acetyl cysteine and/or taurine could be used as treatments in sumatriptan-induced side effects. PMID:28101470

  20. Inhibition of mucin glycosylation by aryl-N-acetyl-alpha-galactosaminides in human colon cancer cells

    SciTech Connect

    Kuan, S.F.; Byrd, J.C.; Basbaum, C.; Kim, Y.S. )

    1989-11-15

    Specific inhibitors of the glycosylation of O-glycosidically linked glycoproteins have not previously been described. When tested for their effects on mucin glycosylation in a mucin-producing colon cancer cell line, LS174T, benzyl-, phenyl-, and p-nitrophenyl-N-acetyl-alpha-galactosaminide inhibited the formation of fully glycosylated mucin in a dose-dependent manner. Free aryl-oligosaccharides were found in the medium of treated cells labeled with ({sup 3}H)glucosamine, ({sup 3}H)galactose, ({sup 3}H)fucose, ({sup 3}H)mannosamine, or phenyl-alpha-(6-{sup 3}H) N-acetylgalactosamine. UDP-Gal:GalNAc-beta 1,3-galactosyltransferase was inhibited by aryl-N-acetyl-alpha-galactosaminides but not by a number of other aryl-glycosides. Treatment with these inhibitors also causes reversible morphologic changes including formation of intercellular cysts. Aryl-N-acetyl-alpha-galactosaminides can be useful for the structural and functional studies of mucin macromolecules and other O-linked glycoproteins.

  1. N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

    PubMed Central

    Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

  2. N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

    PubMed

    Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

  3. The dynamics of conformational isomerization in flexible biomolecules. I. Hole-filling spectroscopy of N-acetyl tryptophan methyl amide and N-acetyl tryptophan amide.

    PubMed

    Dian, Brian C; Longarte, Asier; Winter, Paul R; Zwier, Timothy S

    2004-01-01

    The conformational isomerization dynamics of N-acetyl tryptophan methyl amide (NATMA) and N-acetyl tryptophan amide (NATA) have been studied using the methods of IR-UV hole-filling spectroscopy (HFS) and IR-induced population transfer spectroscopy (IR-PTS), which were developed for this purpose. Single conformations of these molecules were selectively excited in well-defined NH stretch fundamentals. This excess energy was used to drive conformational isomerization. By carrying out the infrared excitation early in a supersonic expansion, the excited molecules were recooled into their zero-point levels, partially refilling the hole created in the ground state population of one of the conformers, and creating gains in population in other conformers. These changes in population were detected using laser-induced fluorescence downstream in the expansion. In HFS, the IR wavelength is fixed and the UV laser tuned in order to determine where the population went following selective infrared excitation. In IR-PTS, the UV is fixed to monitor the population of a given conformation, and the IR is tuned to record the IR-induced changes in the population of the monitored conformer. Besides demonstrating the capability of the experiment to change the downstream conformational population distribution, the IR-PTS scans were used to extract two quantitative results: (i) The fractional populations of the conformers in the absence of the infrared, and (ii) the isomerization quantum yields for each of the six unique amide NH stretch fundamentals (three conformers each with two amide groups). The method for obtaining quantum yields is described in detail. In both NATMA and NATA, the quantum yields show modest conformational specificity, but only a hint of vibrational mode specificity. The prospects for the hole-filling technique for providing insight into energy flow in large molecules are discussed, leaving a more detailed theoretical modeling to the adjoining paper [Evans et al. J. Chem

  4. Depolymerization and de-N-acetylation of chitin oligomers in hydrochloric acid.

    PubMed

    Einbu, Aslak; Vårum, Kjell M

    2007-01-01

    The monosaccharide 2-amino-2-deoxy-D-glucose (glucosamine, GlcN) has recently drawn much attention in relation to its use to treat or prevent osteoarthritis in humans. Glucosamine is prepared from chitin, a process that is performed in concentrated acid, such as hydrochloric acid. This process involves two acid-catalyzed processes, that is, the hydrolysis of the glycosidic linkages (depolymerization) and of the N-acetyl linkages (de-N-acetylation). The depolymerization reaction has previously been found to be much faster compared to the deacetylation, with the consequence that the chitin chain will first be hydrolyzed to the monomer 2-acetamido-2-deoxy-D-glucose (N-acetylglucosamine, GlcNAc) which is subsequently deacetylated. We have found that the chitin disaccharide GlcNAc(1-->4)GlcNAc could be completely hydrolyzed to the monosaccharide GlcNAc with negligible concomitant de-N-acetylation, and the chitin disaccharide and monosaccharide were further used to study the depolymerization reaction and the de-N-acetylation reaction, respectively. The reactions were performed in hydrochloric acid as a function of acid concentration (3-12 M) and temperature (20-35 degrees C), and 1H-NMR spectroscopy was used to monitor the reaction rates. The 1H NMR spectrum of GlcNAc in concentrated (12 M) and deuterated hydrochloric acid at 25 degrees C was assigned. The glucofuranosyl oxazolinium (3) ion was found to exist in equilibrium with the alpha- and beta-anomers of the pyranose form of GlcNAc, where 3 was present in half the total molar concentrations of the two anomeric forms of GlcNAc. At lower acid concentration (3-6 M), only trace concentrations of 3 could be detected. The rate of de-N-acetylation of GlcNAc was determined as a function of hydrochloric acid concentration, showing a maximum at 6 M and decreasing by a factor of 2 upon decreasing or increasing the acid concentration to 3 or 12 M. The activation energy for hydrolysis of the N-acetyl linkage of GlcNAc was

  5. Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

    SciTech Connect

    Yang, Xiupei; Lin, Jia; Liao, Xiulin; Zong, Yingying; Gao, Huanhuan

    2015-06-15

    Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH{sub 3}{sup +} moiety of doxorubicin and the −COO{sup −} moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum.

  6. Biologic properties and vaccine potential of the staphylococcal poly-N-acetyl glucosamine surface polysaccharide.

    PubMed

    Maira-Litran, Tomas; Kropec, Andrea; Goldmann, Donald; Pier, Gerald B

    2004-02-17

    Staphylococci have become the most common causes of nosocomial bacterial infections, and this fact, along with increasing problems associated with antimicrobial resistance, spurs the need for finding immunotherapeutic alternatives to prevent and possibly treat these infections. Most virulent, clinical isolates of both coagulase-negative staphylococci (CoNS) and Staphylococcus aureus carry the ica locus which encodes proteins that synthesize a polymer of beta-1-6 linked N-acetyl glucosamine residues (PNAG). Animal studies have shown purified PNAG can elicit protective immunity against both CoNS and S. aureus, suggesting its potential as a broadly protective vaccine for many clinically important strains of staphylococci.

  7. Purification and structural characterization of de-N-acetylated form of GD3 ganglioside present in human melanoma tumors.

    PubMed

    Popa, Iuliana; Pons, Alexandre; Mariller, Christophe; Tai, Tadashi; Zanetta, Jean-Pierre; Thomas, Luc; Portoukalian, Jacques

    2007-04-01

    The presence of gangliosides containing de-N-acetylated sialic acids in human tissues has been so far shown by using mouse monoclonal antibodies specific for the de-N-acetylated forms, but the isolation and chemical characterization of such compounds have not yet been performed. Since indirect evidence suggested that de-N-acetylGD3 ganglioside could be present in human melanoma tumors, we analyzed the gangliosides purified from a 500-g pool of those tumors. The de-N-acetylGD3 that was found to migrate just below GD2 in thin-layer chromatography was isolated from the disialogangliosides by high-pressure liquid chromatography using the specific antibody SGR37 to monitor the elution. The amount of antigen was found to be 320 ng per gram of fresh tumor or 0.1% of total gangliosides. Gas chromatography-mass spectrometry analysis of the antibody-positive ganglioside showed that sialic acids were formed of one molecule of N-acetylneuraminic acid and one molecule of neuraminic acid. Radioactive re-N-acetylation of the antigen yielded a GD3-like ganglioside with the radioactive label on the external sialic acid. The constitutive fatty acids were found to differ markedly from those of GD3 and 9-O-acetylGD3 isolated from the same pool of tumors. The major fatty acids were C16:0 and C18:0 in de-N-acetylGD3, whereas GD3 and its 9-O-acetylated derivative contained a large amount of C24:1. These data show that de-N-acetylGD3 ganglioside is indeed present in human melanoma tumors, and the fatty acid content suggests the existence of a de-N-acetylase mostly active on the molecular species of gangliosides with short-chain fatty acids.

  8. N-Acetyl-l-Cysteine and Cysteamine as New Strategies against Mixed Biofilms of Nonencapsulated Streptococcus pneumoniae and Nontypeable Haemophilus influenzae.

    PubMed

    Domenech, Mirian; García, Ernesto

    2017-02-01

    Acute otitis media, a polymicrobial disease of the middle ear cavity of children, is a significant public health problem worldwide. It is most frequently caused by encapsulated Streptococcus pneumoniae and nontypeable Haemophilus influenzae, although the widespread use of pneumococcal conjugate vaccines is apparently producing an increase in the carriage of nonencapsulated S. pneumoniae Frequently, pneumococci and H. influenzae live together in the human nasopharynx, forming a self-produced biofilm. Biofilms present a global medical challenge since the inherent antibiotic resistance of their producers demands the use of large doses of antibiotics over prolonged periods. Frequently, these therapeutic measures fail, contributing to bacterial persistence. Here, we describe the development of an in vitro nonencapsulated S. pneumoniae-nontypeable H. influenzae biofilm system with polystyrene or glass-bottom plates. Confocal laser scanning microscopy and specific fluorescent labeling of pneumococcal cells with Helix pomatia agglutinin revealed an even distribution of both species within the biofilm. This simple and robust protocol of mixed biofilms was used to test the antimicrobial properties of two well-known antioxidants that are widely used in the clinical setting, i.e., N-acetyl-l-cysteine and cysteamine. This repurposing approach showed the high potency of N-acetyl-l-cysteine and cysteamine against mixed biofilms of nonencapsulated S. pneumoniae and nontypeable H. influenzae Decades of clinical use mean that these compounds are safe to use, which may accelerate their evaluation in humans. Copyright © 2017 American Society for Microbiology.

  9. N-Acetyl-l-Cysteine and Cysteamine as New Strategies against Mixed Biofilms of Nonencapsulated Streptococcus pneumoniae and Nontypeable Haemophilus influenzae

    PubMed Central

    García, Ernesto

    2016-01-01

    ABSTRACT Acute otitis media, a polymicrobial disease of the middle ear cavity of children, is a significant public health problem worldwide. It is most frequently caused by encapsulated Streptococcus pneumoniae and nontypeable Haemophilus influenzae, although the widespread use of pneumococcal conjugate vaccines is apparently producing an increase in the carriage of nonencapsulated S. pneumoniae. Frequently, pneumococci and H. influenzae live together in the human nasopharynx, forming a self-produced biofilm. Biofilms present a global medical challenge since the inherent antibiotic resistance of their producers demands the use of large doses of antibiotics over prolonged periods. Frequently, these therapeutic measures fail, contributing to bacterial persistence. Here, we describe the development of an in vitro nonencapsulated S. pneumoniae-nontypeable H. influenzae biofilm system with polystyrene or glass-bottom plates. Confocal laser scanning microscopy and specific fluorescent labeling of pneumococcal cells with Helix pomatia agglutinin revealed an even distribution of both species within the biofilm. This simple and robust protocol of mixed biofilms was used to test the antimicrobial properties of two well-known antioxidants that are widely used in the clinical setting, i.e., N-acetyl-l-cysteine and cysteamine. This repurposing approach showed the high potency of N-acetyl-l-cysteine and cysteamine against mixed biofilms of nonencapsulated S. pneumoniae and nontypeable H. influenzae. Decades of clinical use mean that these compounds are safe to use, which may accelerate their evaluation in humans. PMID:27919900

  10. Life extension by diet restriction and N-acetyl-L-cysteine in genetically heterogeneous mice.

    PubMed

    Flurkey, Kevin; Astle, Clinton M; Harrison, David E

    2010-12-01

    We used a heterogeneous stock of mice-UM-HET3, the first generation offspring of CByB6F1/J and C3D2F1/J parents-to test effects of six antiaging treatments on life span. In the first report of diet restriction in a structured, segregating heterogeneous population, we observed essentially the same increases in mean and maximum life span as found in CByB6F1/J hybrid positive controls. We also report results of treatment with N-acetyl-L-cysteine started at 7 months, and aspirin, nitroflurbiprofen, 4-hydroxy phenyl N-tert-butyl nitrone, and nordihydroguaiaretic acid, all started at 16-18 months. Only male UM-HET3 mice receiving N-acetyl-L-cysteine had significantly increased life span, and this may have been due to treatment-related inadvertent diet restriction. The other agents had no significant effects on life span. The use of UM-HET3 mice helps assure that these results are not the result of unresponsiveness of a single genotype but that they more broadly represent laboratory mice.

  11. Life Extension by Diet Restriction and N-Acetyl-L-Cysteine in Genetically Heterogeneous Mice

    PubMed Central

    Flurkey, Kevin; Astle, Clinton M.

    2010-01-01

    We used a heterogeneous stock of mice—UM-HET3, the first generation offspring of CByB6F1/J and C3D2F1/J parents—to test effects of six antiaging treatments on life span. In the first report of diet restriction in a structured, segregating heterogeneous population, we observed essentially the same increases in mean and maximum life span as found in CByB6F1/J hybrid positive controls. We also report results of treatment with N-acetyl-L-cysteine started at 7 months, and aspirin, nitroflurbiprofen, 4-hydroxy phenyl N-tert-butyl nitrone, and nordihydroguaiaretic acid, all started at 16–18 months. Only male UM-HET3 mice receiving N-acetyl-L-cysteine had significantly increased life span, and this may have been due to treatment-related inadvertent diet restriction. The other agents had no significant effects on life span. The use of UM-HET3 mice helps assure that these results are not the result of unresponsiveness of a single genotype but that they more broadly represent laboratory mice. PMID:20819793

  12. CORRELATION BETWEEN THE OPTICAL AND MAGNETIC PROPERTIES OF FERRIC N-ACETYLATED HEME OCTAPEPTIDE COMPLEXES

    SciTech Connect

    Yang, E.K.; Sauer, K.

    1980-05-01

    The room temperature magnetic susceptibility of the complexes of the ferric N-acetylated heme octapeptide (N-H8PT) from horse heart cytochrome c is known to be generally consistent with the absorption and magnetic circular dichroism (MCD) spectra of these complexes. However, the N-acetylated methionine complex of the N-H8PT, which has axial coordination identical to that of the parent molecule, is found to exhibit a thermal mixture of high spin (S=5/2) and low spin (S=1/2) states. The temperature dependence of the magnetic susceptibility of the N-acetylmethionine complex yields {Delta}H{sup 0} = -7.6kca1/mole and {Delta}S° = -25.9 e.u. for a high to low spin transition. The electron spin resonance (ESR) spectrum of the N-acetylmethionine complex indicates a low spin ground state, with g values at 1.51, 2.31, and 2.91, which are distinct from those of cytochrome c. The axial ({Delta}) and rhombic (V) distortion parameters of the {sup 2}T{sub 2g} state correspond to 2.96{lambda} and 1.94{lambda}, respectively, where {lambda} is the spin-orbit coupling constant. A model is proposed to account for the uniqueness of the N-acetylmethionine complex: a change in the Fe-S distance may play a role in regulating the redox properties of cytochrome c.

  13. Interactions of egg yolk phosphatidylcholine with cholesteryl polyethoxy neoglycolipids containing N-acetyl- D-glucosamine

    NASA Astrophysics Data System (ADS)

    Kemoun, Rachida; Gelhausen, Micaèle; Besson, Françoise; Lafont, Dominique; Buchet, René; Boullanger, Paul; Roux, Bernard

    1999-03-01

    Series of neoglycolipids containing cholesteryl and N-acetyl- D-glucosaminyl groups were synthesized with various ethoxy linkers. Their self aggregations and intermolecular interactions, without and with egg yolk phosphatidylcholine (EYPC), were characterized in dry and hydrated states, by using infrared spectroscopy. The neoglycolipids in the dry state formed intermolecular hydrogen bonds between the CO and N-H or O-H groups of N-acetyl- D-glucosamine (GlcNAc). In the presence of EYPC, these intermolecular interactions were broken and new hydrogen bonds, involving the phosphate group of EYPC and N-H or O-H groups of GlcNAc of neoglycolipid, were formed. The presence of water molecules altered these intermolecular hydrogen bonds. The CO groups of EYPC were not affected by the presence of neoglycolipids, either in hydrated or in dry states, indicating that the GlcNAc polar groups interacted mostly with EYPC phosphate residues. The phase transition-temperature of mixtures of EYPC containing either cholesterol or neoglycolipid were similar, indicating that the cholesteryl group of the neoglycolipid interacted in the same manner as cholesterol with hydrocarbon chains of EYPC. Some structural models of molecular interactions of neoglycolipids were discussed in relation with the molecular recognition of wheat germ agglutinin.

  14. Reversible Post-Translational Carboxylation Modulates The Enzymatic Activity Of N-Acetyl-L-Ornithine Transcarbamylase†

    PubMed Central

    Li, Yongdong; Yu, Xiaolin; Ho, Jeremy; Fushman, David; Allewell, Norma M.; Tuchman, Mendel; Shi, Dashuang

    2010-01-01

    N-acetyl-L-ornithine transcarbamylase (AOTCase), rather than ornithine transcarbamylase (OTCase), is the essential carbamylase enzyme in the arginine biosynthesis of several plant and human pathogens. The specificity of this unique enzyme provides a potential target for controlling the spread of these pathogens. Recently, several crystal structures of AOTCase from Xanthomonas campestris (xc) have been determined. In these structures, an unexplained electron density at the tip of Lys302 side-chain was observed. Using 13C NMR spectroscopy, we show herein that Lys302 is post-translationally carboxylated. The structure of wild-type AOTCase complexed with the bisubstrate analogue, Nδ-(phosphonoacetyl)-Nα-acetyl-L-ornithine (PALAO), indicates that the carboxyl group on Lys302 forms a strong hydrogen bonding network with surrounding active site residues, Lys252, Ser253, His293, and Glu92 from the adjacent subunit either directly or via a water molecule. Furthermore, the carboxyl group is involved in binding N-acetyl-L-ornithine via a water molecule. Activity assays with the wild-type enzyme and several mutants demonstrate that the post translational modification of lysine 302 has an important role in catalysis. PMID:20695527

  15. Urinary mutagenicity and N-acetylation phenotype in textile industry workers exposed to arylamines

    SciTech Connect

    Sinues, B.; Perez, J.; Bernal, M.L.; Saenz, M.A.; Lanuza, J.; Bartolome, M. )

    1992-09-15

    Primary aromatic amines have been identified epidemiologically as human carcinogens. It has been suggested that the target organ affected by aromatic amines is dependent on the rate of metabolic activation. Epidemiological studies have shown an association between low acetyl transferase activity and bladder cancer risk. On this basis, our working hypothesis was that the slow acetylators could follow in a higher extent the metabolic pathway independent of N-acetylation, leading to the excretion of conjugates of electrophyles with glucuronic acid. The instability of these glucuronides could be responsible for the association between arylamine-induced bladder cancer and slow acetylator phenotype. A total of 153 individuals were included in this study: 70 exposed to arylamines (working in textile industry) and 83 nonexposed. The following parameters were determined in urine: mutagenic index in the absence of metabolic activation, S9; mutagenic index in the presence of S9; and the mutagenic index after incubation of the urine with beta-glucuronidase. All individuals were phenotyped according to their capacity of N-acetylation by using isoniazid as drug test. The results show that the mutagenic index after incubation of the urine with beta-glucuronidase is statistically higher in exposed subjects when compared with nonexposed individuals (P less than 0.001), this parameter being statistically higher among exposed subjects who were slow acetylators than among rapid metabolizers, independent of the fact that they were smokers or nonsmokers. There were no significant differences between groups for the mutagenicity in urine not incubated with beta-glucuronidase.

  16. P-selectin upregulation in bleomycin induced lung injury in rats: effect of N-acetyl-L-cysteine

    PubMed Central

    Serrano-Mollar, A; Closa, D; Cortijo, J; Morcillo, E; Prats, N; Gironella, M; Panes, J; Rosello-Catafau, J; Bulbena, O

    2002-01-01

    Background: A number of adhesion molecules are involved in the process of neutrophil infiltration into the lung. P-selectin is one of these neutrophil-endothelial cell adhesion molecules. A study was undertaken to examine the involvement of P-selectin in the development of bleomycin induced inflammation and the ability of N-acetyl-L-cysteine to reduce the potential expression of this selectin in rats. Methods: N-acetyl-L-cysteine (3 mmol/kg po) was administered daily for seven days prior to bleomycin administration (2.5 U/kg). The kinetics of P-selectin expression and the effect of N-acetyl-L-cysteine after bleomycin treatment were measured using radiolabelled antibodies. P-selectin localisation was evaluated by immunohistochemistry and neutrophil infiltration was assessed by myeloperoxidase activity. Results: Bleomycin administration resulted in an upregulation of P-selectin at 1 hour, returning to baseline at 3 hours. Myeloperoxidase activity showed a significant increase at 6 hours after bleomycin administration that lasted for 3 days. N-acetyl-L-cysteine treatment completely prevented these increases. Conclusion: Upregulation of P-selectin in the lung is associated with neutrophil recruitment in response to bleomycin. The beneficial effect of N-acetyl-L-cysteine on bleomycin induced lung injury may be explained in part by the prevention of neutrophil recruitment in the inflammatory stage of the disease. PMID:12096208

  17. A simple preparation of half N-acetylated chitosan highly soluble in water and aqueous organic solvents.

    PubMed

    Kubota, N; Tatsumoto, N; Sano, T; Toya, K

    2000-03-10

    A simple and improved method of preparing highly soluble chitosan (half N-acetylated chitosan) was developed using a series of chitosan samples of low molecular weights, and the solubility of the half N-acetylated chitosan in water and organic solvents was investigated in detail. To reduce the molecular weight, chitosan was treated with NaBO3 under the condition that chitosan was homogeneously dissolved in aqueous acetic acid. Weight-average molecular weights of the obtained chitosan samples were determined using a size-exclusion chromatography system equipped with a low-angle laser light-scattering photometer. Each chitosan sample was then N-acetylated with acetic anhydride under the condition that chitosan was homogeneously dissolved in aqueous acetic acid again. The water solubility of the half N-acetylated chitosan thus prepared increased with decreasing molecular weight. From 1H NMR spectroscopy, it was suggested that the sequence of N-acetylglucosamine and glucosamine residues was random. The solubility of the half N-acetylated chitosan of low molecular weight was rather high even in aqueous dimethylacetamide and dimethylsulfoxide.

  18. N-Acetyl-L-Cysteine Prevents Stress-Induced Desmin Aggregation in Cellular Models of Desminopathy

    PubMed Central

    Bailleux, Virginie; Simon, Stéphanie; Leccia, Emilie; Gausseres, Blandine; Briki, Fatma; Vicart, Patrick; Batonnet-Pichon, Sabrina

    2013-01-01

    Mutations within the human desmin gene are responsible for a subcategory of myofibrillar myopathies called desminopathies. However, a single inherited mutation can produce different phenotypes within a family, suggesting that environmental factors influence disease states. Although several mouse models have been used to investigate organ-specific desminopathies, a more general mechanistic perspective is required to advance our knowledge toward patient treatment. To improve our understanding of disease pathology, we have developed cellular models to observe desmin behaviour in early stages of disease pathology, e.g., upon formation of cytoplasmic desmin aggregates, within an isogenic background. We cloned the wildtype and three mutant desmin cDNAs using a Tet-On Advanced® expression system in C2C12 cells. Mutations were selected based on positioning within desmin and capacity to form aggregates in transient experiments, as follows: DesS46Y (head domain; low aggregation), DesD399Y (central rod domain; high aggregation), and DesS460I (tail domain; moderate aggregation). Introduction of these proteins into a C2C12 background permitted us to compare between desmin variants as well as to determine the role of external stress on aggregation. Three different types of stress, likely encountered during muscle activity, were introduced to the cell models—thermal (heat shock), redox-associated (H2O2 and cadmium chloride), and mechanical (stretching) stresses—after which aggregation was measured. Cells containing variant DesD399Y were more sensitive to stress, leading to marked cytoplasmic perinuclear aggregations. We then evaluated the capacity of biochemical compounds to prevent this aggregation, applying dexamethasone (an inducer of heat shock proteins), fisetin or N-acetyl-L-cysteine (antioxidants) before stress induction. Interestingly, N-acetyl-L-cysteine pre-treatment prevented DesD399Y aggregation during most stress. N-acetyl-L-cysteine has recently been described

  19. Biosynthesis of uridine diphosphate N-acetyl-L-fucosamine in a cell-free system from Salmonella arizonae O:59.

    PubMed

    Druzhinina, T N; Kalinchuk, N A; Shibaev, V N

    2005-01-01

    The conversion of uridine diphosphate N-acetyl-D-glucosamine into uridine diphosphate N-acetyl-L-fucosamine was demonstrated with enzymes from cytoplasmic fraction of Salmonella arizonae O:59 cells in the presence of NAD+ (NADP+) and NADPH. The reaction product was identified by ion-pair, reverse-phase HPLC with the use of synthetic nucleoside diphosphate sugar standards under conditions specially developed for separation of uridine diphosphate 2-acetamido-2,6-dideoxyhexoses. L-Fucose dehydrogenase from porcine liver was shown to be applicable for determination of N-acetyl-L-fucosamine, this enzyme being used to confirm L-configuration of the amino sugar residue in the sugar nucleotide formed.

  20. Chitinase but N-acetyl-β-D-glucosaminidase production correlates to the biomass decline in Penicillium and Aspergillus species.

    PubMed

    Pusztahelyi, Tünde; Pócsi, István

    2014-06-01

    Hydrolytic enzyme production is typical of the autolysis in filamentous fungi; however, less attention has been given to the physiological role of the enzymes. Here, the aim was to investigate the possible relation of the chitinolytic enzymes to the changes in the biomass in some filamentous fungi of high importance for pharmaceutical or food industry. In Penicillium and Aspergillus filamentous fungi, which showed different characteristics in submerged cultures, the growth and biomass decline rates were calculated and correlated to the chitinase and N-acetyl-β-D-glucosaminidase enzyme productions. Correlation was found between the biomass decrease rate and the chitinase level at the stationary growth phase; while chitinase production covariates negatively with N-acetyl-β-D-glucosaminidase activities. The chitinase production and the intensive autolysis hindered the production of N-acetyl-β-D-glucosaminidase and, therefore, could hinder the cell death in the cultures.

  1. Amelioration of Acute Sequelae of Blast Induced Mild Traumatic Brain Injury by N-Acetyl Cysteine: A Double-Blind, Placebo Controlled Study

    DTIC Science & Technology

    2013-01-23

    participate. Individuals underwent a baseline evaluation and then were randomly assigned to receive either N- acetyl cysteine ( NAC ) or placebo for...Bielefeld EC, Kopke RD, Jackson RL, Coleman JK, Liu J, et al. (2007) Noise protection with N- acetyl -l- cysteine ( NAC ) using a variety of noise exposures...Amelioration of Acute Sequelae of Blast Induced Mild Traumatic Brain Injury by N- Acetyl Cysteine : A Double- Blind, Placebo Controlled Study Michael E

  2. Inhibitory effect of carnosine and N-acetyl carnosine on LPS-induced microglial oxidative stress and inflammation.

    PubMed

    Fleisher-Berkovich, Sigal; Abramovitch-Dahan, Chen; Ben-Shabat, Shimon; Apte, Ron; Beit-Yannai, Elie

    2009-07-01

    Chronic inflammation and oxidative stress have been implicated in the pathogenesis of neurodegenerative diseases. A growing body of research focuses on the role of microglia, the primary immune cells in the brain, in modulating brain inflammation and oxidative stress. One of the most abundant antioxidants in the brain, particularly in glia, is the dipeptide carnosine, beta-alanyl-L-histidine. Carnosine is believed to be involved in cellular defense such as free radical detoxification and inhibition of protein cross-linking. The more stable N-acetyl derivative of carnosine has also been identified in the brain. The aim of the present study was to examine the role of carnosine and N-acetyl carnosine in the regulation of lipopolysaccharide (LPS)-induced microglial inflammation and oxidative damage. In this study, BV2 microglial cells were stimulated with bacterial LPS, a potent inflammatory stimulus. The data shows that both carnosine and N-acetyl carnosine significantly attenuated the LPS-induced nitric oxide synthesis and the expression of inducible nitric oxide synthase by 60% and 70%, respectively. By competitive spectrophotometric measurement and electrospray mass spectrometry analysis, we demonstrated a direct interaction of N-acetyl carnosine with nitric oxide. LPS-induced TNFalpha secretion and carbonyl formation were also significantly attenuated by both compounds. N-acetyl carnosine was more potent than carnosine in inhibiting the release of the inflammatory and oxidative stress mediators. These observations suggest the presence of a novel regulatory pathway through which carnosine and N-acetyl carnosine inhibit the synthesis of microglial inflammatory and oxidative stress mediators, and thus may prove to play a role in brain inflammation.

  3. Concurrent esterification and N-acetylation of amino acids with orthoesters: A useful reaction with interesting mechanistic implications

    PubMed Central

    Gibson, Sarah; Romero, Dickie; Jacobs, Hollie K.; Gopalan, Aravamudan S.

    2010-01-01

    The concurrent esterification and N-acetylation of amino acids has been studied with triethyl orthoacetate (TEOA) and triethyl orthoformate (TEOF). In a surprising finding, only one equivalent of TEOA in refluxing toluene was necessary to convert L-proline and L-phenylalanine to the corresponding N-acetyl ethyl esters in good yield. The same transformation using TEOF was not effective. Stereochemical outcome and stoichiometric studies as well as structural variation of the amino acids in this reaction provided unexpected mechanistic insight. PMID:21286246

  4. Quantification of Lysosomal Membrane Permeabilization by Cytosolic Cathepsin and β-N-Acetyl-Glucosaminidase Activity Measurements.

    PubMed

    Jäättelä, Marja; Nylandsted, Jesper

    2015-11-02

    Programmed cell death involving lysosomal membrane permeabilization (LMP) is an alternative cell death pathway induced under various cellular conditions and by numerous cytotoxic stimuli. The method presented here to quantify LMP takes advantage of the detergent digitonin, which creates pores in cellular membranes by replacing cholesterol. The difference in cholesterol content between the plasma membrane (high) and lysosomal membrane (low) allows titration of digitonin to a concentration that permeabilizes the plasma membrane but leaves lysosomal membranes intact. The extent of LMP is determined by measuring the cytosolic activity of lysosomal hydrolases (e.g., cysteine cathepsins) and/or β-N-acetyl-glucosaminidase in the digitonin-extracted cytoplasm and comparing it to the total cellular enzyme activity. Digitonin extraction of the cytosol can be combined with precipitation of protein and/or western blot analysis for detection of lysosomal proteins (e.g., cathepsins).

  5. Expanding the phenotype of hawkinsinuria: new insights from response to N-acetyl-L-cysteine.

    PubMed

    Gomez-Ospina, Natalia; Scott, Anna I; Oh, Gia J; Potter, Donald; Goel, Veena V; Destino, Lauren; Baugh, Nancy; Enns, Gregory M; Niemi, Anna-Kaisa; Cowan, Tina M

    2016-11-01

    Hawkinsinuria is a rare disorder of tyrosine metabolism that can manifest with metabolic acidosis and growth arrest around the time of weaning off breast milk, typically followed by spontaneous resolution of symptoms around 1 year of age. The urinary metabolites hawkinsin, quinolacetic acid, and pyroglutamic acid can aid in identifying this condition, although their relationship to the clinical manifestations is not known. Herein we describe clinical and laboratory findings in two fraternal twins with hawkinsinuria who presented with failure to thrive and metabolic acidosis. Close clinical follow-up and laboratory testing revealed previously unrecognized hypoglycemia, hypophosphatemia, combined hyperlipidemia, and anemia, along with the characteristic urinary metabolites, including massive pyroglutamic aciduria. Treatment with N-acetyl-L-cysteine (NAC) restored normal growth and normalized or improved most biochemical parameters. The dramatic response to NAC therapy supports the idea that glutathione depletion plays a key role in the pathogenesis of hawkinsinuria.

  6. Analysis of urinary N-acetyl-beta-glucosaminidase by capillary zone electrophoresis.

    PubMed

    Friedberg, M; Shihabi, Z K

    1997-07-18

    N-Acetyl-beta-glucosaminidase (NAG), a glycosidase enzyme, present in serum, urine and the renal lysosomes is utilized clinically as an early marker for renal damage preceding the elevation of both blood urea nitrogen and creatinine. NAG is analyzed by CE after incubation of urine samples with the synthetic substrate methylumbelliferyl-beta-D-glucosaminide. The reaction mixture is introduced directly into the instrument without further treatment. The released reaction product, 4-methyl-umbelliferone, is separated at 13.2 kV in a 400 mM borate buffer, pH 8.1. Detection was achieved with either ultraviolet absorption or with fluorescence. The fluorescence detection was more sensitive and gave cleaner electropherograms. The CZE method correlated well with an automated kinetic fluorescent assay. 4-Methyl-umbelliferone conjugated to different substrates is used in the analysis of many enzymes involved in the inborn errors of metabolism.

  7. Glucosamine and N-acetyl glucosamine as new CEST MRI agents for molecular imaging of tumors

    PubMed Central

    Rivlin, Michal; Navon, Gil

    2016-01-01

    The efficacy of glucosamine (GlcN) and N-acetyl glucosamine (GlcNAc) as agents for chemical exchange saturation transfer (CEST) magnetic resonance molecular imaging of tumors is demonstrated. Both agents reflect the metabolic activity and malignancy of the tumors. The method was tested in two types of tumors implanted orthotopically in mice: 4T1 (mouse mammary cancer cells) and MCF7 (human mammary cancer cells). 4T1 is a more aggressive type of tumor than MCF7 and exhibited a larger CEST effect. Two methods of administration of the agents, intravenous (IV) and oral (PO), gave similar results. The CEST MRI observation of lung metastasis was confirmed by histology. The potential of the clinical application of CEST MRI with these agents for cancer diagnosis is strengthened by their lack of toxicity as can be indicated from their wide use as food supplements. PMID:27600054

  8. Metabolomic Analysis of Blood Plasma after Oral Administration of N-acetyl-d-Glucosamine in Dogs

    PubMed Central

    Osaki, Tomohiro; Kurozumi, Seiji; Sato, Kimihiko; Terashi, Taro; Azuma, Kazuo; Murahata, Yusuke; Tsuka, Takeshi; Ito, Norihiko; Imagawa, Tomohiro; Minami, Saburo; Okamoto, Yoshiharu

    2015-01-01

    N-acetyl-d-glucosamine (GlcNAc) is a monosaccharide that polymerizes linearly through (1,4)-β-linkages. GlcNAc is the monomeric unit of the polymer chitin. GlcNAc is a basic component of hyaluronic acid and keratin sulfate found on the cell surface. The aim of this study was to examine amino acid metabolism after oral GlcNAc administration in dogs. Results showed that plasma levels of ectoine were significantly higher after oral administration of GlcNAc than prior to administration (p < 0.001). To our knowledge, there have been no reports of increased ectoine concentrations in the plasma. The mechanism by which GlcNAc administration leads to increased ectoine plasma concentration remains unclear; future studies are required to clarify this mechanism. PMID:26262626

  9. Neuroprotection in rabbit retina with N-acetyl-aspartylglutamate and 2-phosphonyl-methyl pentanedioic acid

    NASA Astrophysics Data System (ADS)

    Hacker, Henry D.; Yourick, Debra L.; Koenig, Michael K.; Slusher, Barbara S.; Meyerhoff, James L.

    1999-06-01

    Retinal tissue is subject to ischemia from diabetic retinopathy and other conditions that affect the retinal vasculature such as lupus erythematosus and temporal arteritis. There is evidence in animal models of reversible ischemia that a therapeutic window exists during early recovery when agents that reduce glutamate activity at its receptor sites can rescue neurons from injury. To model ischemia, we used sodium cyanide (NaCN), to inhibit oxidative metabolism, and 2-deoxyglucose (2-DG) to inhibit glycolysis. Dissociated rabbit retina cells were studied to evaluate the potential neuroprotective effects of N-acetyl-aspartyl-glutamate (MAAG), which competes with glutamate as a low-potency agonist at the NMDA receptor complex. N-acetylated α-linked acidic dipeptidase (NAALADase; the NAAG-hydrolyzing enzyme) is responsible for the hydrolysis of NAAG into glutamate, a neurotransmitter and potent excitotoxin, and N-acetylaspartate. 2-Phosphonyl-methyl pentanedioic acid (PMPA) and β-linked NAAG (β-NAAG), inhibitors of NAALADase, were also tested, since inhibition of NAALADase could reduce synaptic glutamate and increase the concentration of NAAG. We found that metabolic inhibition with NaCN/2-DG for 1 hour caused 50% toxicity as assessed with the MTT assay. Co-treatment with NAAG resulted in dose-dependent protection of up to 55% (p<0.005). When the non-hydrolyzable, NAALADase inhibitor β-NAAG was employed dose-dependent protection of up to 37% was observed (p<0.001). PMPA also showed 48% protection (p<.05-.001) against these insults. These data suggest that NAAG may antagonize the effect of glutamate at the NMDA receptor complex in retina. Inhibition of NAALADase by PMPA and β-NAAG may increase the activity of endogenous NAAG.

  10. N-Acetyl-l-cysteine effects on multi-species oral biofilm formation and bacterial ecology.

    PubMed

    Rasmussen, K; Nikrad, J; Reilly, C; Li, Y; Jones, R S

    2016-01-01

    Future therapies for the treatment of dental decay have to consider the importance of preserving bacterial ecology while reducing biofilm adherence to teeth. A multi-species plaque-derived (MSPD) biofilm model was used to assess how concentrations of N-acetyl-l-cysteine (NAC) (0, 0·1, 1, 10%) affected the growth of complex oral biofilms. Biofilms were grown (n = 96) for 24 h on hydroxyapatite discs in BMM media with 0·5% sucrose. Bacterial viability and biomass formation was examined on each disc using a microtitre plate reader. In addition, fluorescence microscopy and Scanning Electron Microscopy was used to qualitatively examine the effect of NAC on bacterial biofilm aggregation, extracellular components and bacterial morphology. The total biomass was significantly decreased after exposure of both 1% (from 0·48, with a 95% confidence interval of (0·44, 0·57) to 0·35, with confidence interval (0·31, 0·38)) and 10% NAC (0·14 with confidence interval (0·11, 0·17)). 16S rRNA amplicon sequencing analysis indicated that 1% NAC reduced biofilm adherence while preserving biofilm ecology. As a compound with a wide safety margin, N-acetyl-l-cysteine (NAC) has the potential to be used as a long term anti-plaque bacteriostatic agent for managing chronic dental decay without substantially altering biofilm's bacterial ecology. The potential anti-caries benefit of NAC is directly related to reducing the biofilm coverage which reduces the degree of acid generation and the amount of time that the surface is exposed to a lower pH. © 2015 The Society for Applied Microbiology.

  11. Differential neuroprotective effects of carnosine, anserine, and N-acetyl carnosine against permanent focal ischemia.

    PubMed

    Min, Jiangyong; Senut, Marie-Claude; Rajanikant, Krishnamurthy; Greenberg, Eric; Bandagi, Ram; Zemke, Daniel; Mousa, Ahmad; Kassab, Mounzer; Farooq, Muhammad U; Gupta, Rishi; Majid, Arshad

    2008-10-01

    Carnosine (beta-alanyl-L-histidine) has been shown to exhibit neuroprotection in rodent models of cerebral ischemia. In the present study, we further characterized the effects of carnosine treatment in a mouse model of permanent focal cerebral ischemia and compared them with its related peptides anserine and N-acetylated carnosine. We also evaluated the efficacy of bestatin, a carnosinase inhibitor, in ameliorating ischemic brain damage. Permanent focal cerebral ischemia was induced by occlusion of the middle cerebral artery (pMCAO). Mice were subsequently randomly assigned to receive an intraperitoneal injection of vehicle (0.9% saline), carnosine, N-acetyl carnosine, anserine, bestatin alone, or bestatin with carnosine. Infarct size was examined using 2,3,5-triphenyltetrazolium chloride staining 1, 3, and 7 days following pMCAO, and neurological function was evaluated using an 18-point-based scale. Brain levels of carnosine were measured in treated mice using high-performance liquid chromatography 1 day following pMCAO. We demonstrated that treatment with carnosine, but not its analogues, was able to significantly reduce infarct volume and improve neurological function compared with those in vehicle-treated mice. These beneficial effects were maintained for 7 days post-pMCAO. In contrast, compared with the vehicle-treated group, bestatin-treated mice displayed an increase in the severity of ischemic lesion, which was prevented by the addition of carnosine. These new data further characterize the neuroprotective effects of carnosine and suggest that carnosine may be an attractive candidate for testing as a stroke therapy.

  12. Differential Neuroprotective Effects of Carnosine, Anserine, and N-Acetyl Carnosine against Permanent Focal Ischemia

    PubMed Central

    Min, Jiangyong; Senut, Marie-Claude; Rajanikant, Krishnamurthy; Greenberg, Eric; Bandagi, Ram; Zemke, Daniel; Mousa, Ahmad; Kassab, Mounzer; Farooq, Muhammad U.; Gupta, Rishi; Majid, Arshad

    2009-01-01

    Carnosine (β-alanyl-L-histidine) has been shown to exhibit neuroprotection in rodent models of cerebral ischemia. In the present study, we further characterized the effects of carnosine treatment in a mouse model of permanent focal cerebral ischemia and compared them with its related peptides anserine and N-acetylated carnosine. We also evaluated the efficacy of bestatin, a carnosinase inhibitor, in ameliorating ischemic brain damage. Permanent focal cerebral ischemia was induced by occlusion of the middle cerebral artery (pMCAO). Mice were subsequently randomly assigned to receive an intraperitoneal injection of vehicle (0.9% saline), carnosine, N-acetyl carnosine, anserine, bestatin alone, or bestatin with carnosine. Infarct size was examined using 2,3,5-triphenyltetrazolium chloride staining 1, 3, and 7 days following pMCAO, and neurological function was evaluated using an 18-point-based scale. Brain levels of carnosine were measured in treated mice using high-performance liquid chromatography 1 day following pMCAO. We demonstrated that treatment with carnosine, but not its analogues, was able to significantly reduce infarct volume and improve neurological function compared with those in vehicle-treated mice. These beneficial effects were maintained for 7 days post-pMCAO. In contrast, compared with the vehicle-treated group, bestatin-treated mice displayed an increase in the severity of ischemic lesion, which was prevented by the addition of carnosine. These new data further characterize the neuroprotective effects of carnosine and suggest that carnosine may be an attractive candidate for testing as a stroke therapy. PMID:18543335

  13. NagA-dependent uptake of N-acetyl-glucosamine and N-acetyl-chitin oligosaccharides across the outer membrane of Caulobacter crescentus.

    PubMed

    Eisenbeis, Simone; Lohmiller, Stefanie; Valdebenito, Marianne; Leicht, Stefan; Braun, Volkmar

    2008-08-01

    Among the 67 predicted TonB-dependent outer membrane transporters of Caulobacter crescentus, NagA was found to be essential for growth on N-acetyl-beta-D-glucosamine (GlcNAc) and larger chitin oligosaccharides. NagA (93 kDa) has a predicted typical domain structure of an outer membrane transport protein: a signal sequence, the TonB box EQVVIT, a hatch domain of 147 residues, and a beta-barrel composed of 22 antiparallel beta-strands linked by large surface loops and very short periplasmic turns. Mutations in tonB1 and exbBD, known to be required for maltose transport via MalA in C. crescentus, and in two additional predicted tonB genes (open reading frames cc2327 and cc3508) did not affect NagA-mediated GlcNAc uptake. nagA is located in a gene cluster that encodes a predicted PTS sugar transport system and two enzymes that convert GlcNAc-6-P to fructose-6-P. Since a nagA insertion mutant did not grow on and transport GlcNAc, diffusion of GlcNAc through unspecific porins in the outer membrane is excluded. Uptake of GlcNAc into tonB and exbBD mutants and reduction but not abolishment of GlcNAc transport by agents which dissipate the electrochemical potential of the cytoplasmic membrane (0.1 mM carbonyl cyanide 3-chlorophenylhydrazone and 1 mM 2,4-dinitrophenol) suggest diffusion of GlcNAc through a permanently open pore of NagA. Growth on (GlcNAc)(3) and (GlcNAc)(5) requires ExbB and ExbD, indicating energy-coupled transport by NagA. We propose that NagA forms a small pore through which GlcNAc specifically diffuses into the periplasm and functions as an energy-coupled transporter for the larger chitin oligosaccharides.

  14. Pharmacokinetics and N-acetylation metabolism of S-methyl-l-cysteine and trans-S-1-propenyl-l-cysteine in rats and dogs.

    PubMed

    Amano, Hirotaka; Kazamori, Daichi; Itoh, Kenji

    2016-11-01

    1. Pharmacokinetics and N-acetylation metabolism of S-methyl-L-cysteine (SMC) and trans-S-1-propenyl-L-cysteine (S1PC) were examined in rats and dogs. SMC and S1PC (2-5 mg/kg) were well absorbed in both species with high bioavailability (88-100%). 2. SMC and S1PC were excreted only to a small extent in the urine of rats and dogs. The small renal clearance values (<0.03 l/h/kg) indicated the extensive renal reabsorption of SMC and S1PC, which potentially contributed to their long elimination half-lives (>5 h) in dogs. 3. S1PC, but not SMC, underwent N-acetylation extensively in vivo, which can be explained by the relative activities of N-acetylation of S1PC/SMC and deacetylation of their N-acetylated forms, N-acetyl-S1PC/N-acetyl-SMC, in the liver and kidney in vitro. The activities for S1PC N-acetylation were similar to or higher than those for N-acetyl-S1PC deacetylation in liver S9 fractions of rat and dog, whereas liver and kidney S9 fractions of rat and dog had little activity for SMC N-acetylation or considerably higher activities for N-acetyl-SMC deacetylation. 4. Our study demonstrated that the pharmacokinetics of SMC and S1PC in rats and dogs was characterized by high bioavailability and extensive renal reabsorption; however, the extent of undergoing the N-acetylation metabolism was extremely different between SMC and S1PC.

  15. Combined inhibitory effects of low temperature and N-acetyl-l-cysteine on the postovulatory aging of mouse oocytes.

    PubMed

    Li, Qian; Cui, Long-Bo

    2016-04-01

    The postovulatory aging of oocytes eventually affects the development of oocytes and embryos. Oxidative stress is known to accelerate the onset of apoptosis in oocytes and influence their capacity for fertilisation. This study aimed to reveal the roles of temperature and the antioxidant N-acetyl-l-cysteine in preventing the aging of postovulatory mouse oocytes. First, newly ovulated mouse oocytes were cultured at various temperature and time combinations in HCZB medium with varying concentrations of N-acetyl-l-cysteine to assess signs of aging and developmental potential. When cultured in HCZB with 300 μM N-acetyl-l-cysteine at different temperature and incubation time combinations (namely 25°C for 12 h, 15°C for 24 h and 5°C for 12 h), the increase in the susceptibility of oocytes to activating stimuli was efficiently prevented, and the developmental potential was maintained following Sr2+ activation or in vitro fertilisation. After incubation at either 15°C for 36 h or 5°C for 24 h, oocytes that had decreased blastocyst rates displayed unrecoverable abnormal cortical granule distribution together with decreased BCL2 levels, total glutathione concentrations and glutathione/glutathione disulphide (GSH/GSSG) ratios. In conclusion, postovulatory oocyte aging could be effectively inhibited by appropriate N-acetyl-l-cysteine addition at low temperatures. In addition, a simple method for the temporary culture of mature oocytes was established.

  16. Computational Study of Environmental Effects on Torsional Free Energy Surface of N-Acetyl-N'-methyl-L-alanylamide Dipeptide

    ERIC Educational Resources Information Center

    Carlotto, Silvia; Zerbetto, Mirco

    2014-01-01

    We propose an articulated computational experiment in which both quantum mechanics (QM) and molecular mechanics (MM) methods are employed to investigate environment effects on the free energy surface for the backbone dihedral angles rotation of the small dipeptide N-Acetyl-N'-methyl-L-alanylamide. This computation exercise is appropriate for an…

  17. N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine, a new urinary metabolite of acrylonitrile and oxiranecarbonitrile.

    PubMed

    Linhart, I; Smejkal, J; Novák, J

    1988-01-01

    Two mercapturic acids, i.e., N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CHEMA) and N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA), were isolated from the urine of rats dosed with four successive doses of oxiranecarbonitrile (glycidonitrile, GN), 5 mg/kg, a reactive metabolic intermediate of acrylonitrile (AN). GC-MS analysis of methylated urine extracts from both AN- and GN-dosed rats showed another mercapturate which was identified as N-acetyl-S-(1-cyanoethenyl)-L-cysteine (1-CEMA) methyl ester using an authentic reference sample. The mass spectrum of this compound was very similar to that of a methylated metabolite of AN tentatively identified by Langvardt et al. (1980) as N-acetyl-3-carboxy-5-cyanothiazane (ACCT). In contrast, no ACCT was found in rats dosed with either GN or AN. Hence, there is no evidence for the formation of ACCT or its isomers in rats dosed with AN or GN. The methyl ester of 1-CEMA is formed artificially by dehydration of CHEMA methyl ester in the injector of the gas chromatograph.

  18. Computational Study of Environmental Effects on Torsional Free Energy Surface of N-Acetyl-N'-methyl-L-alanylamide Dipeptide

    ERIC Educational Resources Information Center

    Carlotto, Silvia; Zerbetto, Mirco

    2014-01-01

    We propose an articulated computational experiment in which both quantum mechanics (QM) and molecular mechanics (MM) methods are employed to investigate environment effects on the free energy surface for the backbone dihedral angles rotation of the small dipeptide N-Acetyl-N'-methyl-L-alanylamide. This computation exercise is appropriate for an…

  19. Isolation of a novel N-acetyl-D-lactosamine specific lectin from Alocasia cucullata (Schott.).

    PubMed

    Kaur, Amandeep; Kamboj, Sukhdev Singh; Singh, Jatinder; Saxena, A K; Dhuna, Vikram

    2005-11-01

    An N-acetyl-D: -lactosamine (LacNAc) specific lectin from tubers of Alocasia cucullata was purified by affinity chromatography on asialofetuin-linked amino activated silica. The pure lectin showed a single band in SDS-PAGE at pH 8.8 and was a homotetramer with a subunit molecular mass of 13.5 kDa and native molecular mass of 53 kDa. It was heat stable up to 55 degrees C for 15 min and showed optimum hemagglutination activity from pH 2 to 11. The lectin was affected by denaturing agents such as urea (2 M: ), thiourea (2 M: ) and guanidine-HCl (0.5 M: ) and did not require Ca2+ and Mn2+ for its activity. It was a potent mitogen at 10 microg/ml towards human peripheral blood mononuclear cells with 50% growth inhibitory potential towards SiHa (human cervix ) cancer cell line at 100 microg/ml.

  20. The Role of Poly N Acetyl Glucosamine Nanofibers in Cutaneous Wound Healing

    NASA Astrophysics Data System (ADS)

    Buff-Lindner, Amanda Haley

    Treatment of cutaneous wounds with poly-N-acetyl-glucosamine nanofibers (pGlcNAc), a novel polysaccharide material derived from a marine diatom, results in increases in wound closure, antibacterial activities and innate immune responses. Treatment with nanofibers results in increased defensin, small antimicrobial peptides, expression both in vitro and in vivo. Induction of defensin expression results in bacterial clearance in a cutaneous wound model. Our data show that Akt1 plays a central role in the regulation of these activities. Interestingly, pGlcNAc treatment of cutaneous wounds in mice results in decreased scar sizes. Additionally, treatment of cutaneous wounds with pGlcNAc results in increased elasticity and a rescue of tensile strength. Masson Trichrome staining suggests that pGlcNAc treated wounds exhibit decreased collagen content as well as increased collagen alignment with collagen fibers oriented similarly to unwounded tissue. Utilizing a fibrin gel assay to analyze the effect of pGlcNAc nanofiber treatment on fibroblast alignment in vitro, pGlcNAc stimulation of embedded fibroblasts results in fibroblasts alignment as compared to untreated controls, by a process that is Akt1 dependent. Our data show that in Akt1 null animals pGlcNAc treatment does not increase tensile strength or elasticity. Taken together, our findings suggest that pGlcNAc nanofibers stimulate an Akt1 dependent pathway that results in wound closure, the proper alignment of fibroblasts, decreased scarring, and increased tensile strength during cutaneous wound healing.

  1. N-Acetyl Cysteine (NAC)-Directed Detoxification of Methacryloxylethyl Cetyl Ammonium Chloride (DMAE-CB).

    PubMed

    Jiao, Yang; Ma, Sai; Li, Jing; Shan, Lequn; Wang, Yingjie; Tian, Min; Yang, Yanwei; Sun, Jinlong; Ban, Jinghao; Chen, Jihua

    2015-01-01

    Methacryloxylethyl cetyl ammonium chloride (DMAE-CB) is a polymerizable antibacterial monomer and has been proved as an effective strategy to achieve bioactive bonding with reliable bacterial inhibitory effects. However, the toxicity of DMAE-CB may hamper its wide application in clinical situations. Thus, this study was designed to investigate the toxicity of DMAE-CB and explore the possible protective effects of N-acetyl cysteine (NAC). High performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) analysis showed that chemical binding of NAC and DMAE-CB occurred in a time dependent manner. Pre-incubation of fourty-eight hours is required for adequate reaction between DMAE-CB and NAC. DMAE-CB reduced human dental pulp cells (hDPCs) viability in a dose-dependent manner. The toxic effects of DMAE-CB were accompanied by increased reactive oxygen species (ROS) level and reduced glutathione (GSH) content. NAC alleviated DMAE-CB-induced oxidative stress. Annexin V/ Propidium Iodide (PI) staining and Hoechst 33342 staining indicated that DMAE-CB induced apoptosis. Collapsed mitochondrial membrane potential (MMP) and activation of caspase-3 were also observed after DMAE-CB treatment. NAC rescued hDPCs from DMAE-CB-induced apoptosis, accompanied by lower level of MMP loss and caspase-3 activity. This study assists to elucidate the mechanism underlying the cytotoxic effects of DMAE-CB and provides theoretical supports for the searching of effective strategies to reduce toxicity of quaternary ammonium dental monomers.

  2. An Additive Effect of Oral N-Acetyl Cysteine on Eradication of Helicobacter pylori

    PubMed Central

    Hamidian, Seyed Mohammad-Taghi; Aletaha, Najmeh-sadat; Taslimi, Reza; Montazeri, Mohammad

    2015-01-01

    Background. Helicobacter pylori is highly adapted to the gastric environment where it lives within or beneath the gastric mucous layer. The aim of this study was to evaluate whether the addition of N-acetyl cysteine to the treatment regimen of H. pylori infection would affect eradication rates of the disease. Methods. A total of 79 H. pylori positive patients were randomized to two therapeutic groups. Both groups received a 14-day course of three-drug regimen including amoxicillin/clarithromycin/omeprazole. Experimental group (38 subjects) received NAC, and control group (41 subjects) received placebo, besides three-drug regimen. H. pylori eradication was evaluated by urea breath test at least 4 weeks after the cessation of therapy. Results. The rate of H. pylori eradication was 72.9% and 60.9% in experimental and control groups, respectively (P = 0.005). By logistic regression modeling, female gender (OR 3.68, 95% CI: 1.06–5.79; P = 0.040) and treatment including NAC (OR 1.88, 95% CI: 0.68–3.15; P = 0.021) were independent factors associated with H. pylori eradication. Conclusion. The results of the present study show that NAC has an additive effect on the eradication rates of H. pylori obtained with three-drug regimen and appears to be a promising means of eradicating H. pylori infection. PMID:26421191

  3. Synthesis, characterization, antibacterial activity and quantum chemical studies of N'-Acetyl propane sulfonic acid hydrazide

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Alyar, Hamit; Ozdemir, Ummuhan Ozmen; Sahin, Omer; Kaya, Kerem; Ozbek, Neslihan; Gunduzalp, Ayla Balaban

    2015-08-01

    A new N'-Acetyl propane sulfonic acid hydrazide, C3H7sbnd SO2sbnd NHsbnd NHsbnd COCH3 (Apsh, an sulfon amide compound) has been synthesized for the first time. The structure of Apsh was investigated using elemental analysis, spectral (IR, 1H/13C NMR) measurements. In addition, molecular structure of the Apsh was determined by single crystal X-ray diffraction technique and found that the compound crystallizes in monoclinic, space group P 21/c. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The structure of Apsh is optimized using Density Functional Theory (DFT) method. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The theoretical IR frequencies are found to be in good agreement with the experimental IR frequencies. Nonlinear optical (NLO) behaviour of Apsh is also examined by the theoretically predicted values of dipole moment (μ), polarizability (α0) and first hyperpolarizability (βtot). The antibacterial activities of synthesized compound were studied against Gram positive bacteria: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 23212, Staphylococcus epidermidis ATCC 34384, Gram negative bacteria: Eschericha coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70063 by using microdilution method (as MICs) and disc diffusion method.

  4. N-acetyl-cysteine attenuates neuropathic pain by suppressing matrix metalloproteinases.

    PubMed

    Li, Jiajie; Xu, Lujie; Deng, Xueting; Jiang, Chunyi; Pan, Cailong; Chen, Lu; Han, Yuan; Dai, Wenling; Hu, Liang; Zhang, Guangqin; Cheng, Zhixiang; Liu, Wentao

    2016-08-01

    The treatment of neuropathic pain remains a clinical challenge because of its unclear mechanisms and broad clinical morbidity. Matrix metalloproteinase (MMP)-9 and MMP-2 have previously been described as key components in neuropathic pain because of their facilitation of inflammatory cytokine maturation and induction of neural inflammation. Therefore, the inhibition of MMPs may represent a novel therapeutic approach to the treatment of neuropathic pain. In this study, we report that N-acetyl-cysteine (NAC), which is a broadly used respiratory drug, significantly attenuates neuropathic pain through a unique mechanism of MMP inhibition. Both the in vitro (0.1 mM) and in vivo application of NAC significantly suppressed the activity of MMP-9/2. Orally administered NAC (50, 100, and 200 mg/kg) not only postponed the occurrence but also inhibited the maintenance of chronic constrictive injury (CCI)-induced neuropathic pain in rats. The administration of NAC blocked the maturation of interleukin-1β, which is a critical substrate of MMPs, and markedly suppressed the neuronal activation induced by CCI, including inhibiting the phosphorylation of protein kinase Cγ, NMDAR1, and mitogen-activated protein kinases. Finally, NAC significantly inhibited CCI-induced microglia activation but elicited no notable effects on astrocytes. These results demonstrate an effective and safe approach that has been used clinically to alleviate neuropathic pain through the powerful inhibition of the activation of MMPs.

  5. [N-acetyl-beta-hexosaminidase--marker of damage to renal proximal tubules].

    PubMed

    Kepka, Alina; Szajda, Sławomir D; Jankowska, Anna; Waszkiewicz, Napoleon; Chojnowska, Sylwia; Zwierz, Krzysztof

    2008-09-01

    Cells of the renal epithelium synthesize and excrete to urine many enzymes. Among more than 50 enzymes produced by epithelial cells of proximal tubules, only few have a diagnostic value. Determination of the enzymatic activities in urine is sensitive and not invasive method for evaluation the function of renal tubules. Urinary N-acetyl-beta-hexosaminidase (HEX) activity is approved and practically utilized marker of the renal function. HEX is a lysosomal exoglycosidase taking part in catabolism of the sugar chains of glycoconjugates (glycoproteins, glycolipids and proteoglycans). HEX catalyses release of N-acetylglucosamine and N-acetylgalactosamine from a non reducing ends of glycoconjugates. In urine of healthy persons activity of HEX is negligible, but significantly increases after damage to the proximal tubules. The cells of renal proximal tubules are very sensitive to hypoxia. Therefore all renal processes with hypoxia lead to dysfunction of proximal renal tubules and release HEX to urine. Increased activity of HEX in urine was found after intoxication by heavy metals, nephrotoxic drugs, contrast media, fewer, bacterial as well as immunological nephritis and hypertension, diabetes, neoplasms and during renal graft rejection. In the paper we presented review of literature concerning HEX, and its presence in renal tissue and urine, as well as application in diagnostics.

  6. Characterization of N-Acetyl-Tryptophan Degradation in Protein Therapeutic Formulations.

    PubMed

    Hogan, Kyle L; Leiske, Danielle; Salisbury, Cleo M

    2017-08-24

    N-Acetyl-tryptophan (NAT) is used as a stabilizer for preparations of human serum albumin and has more recently been demonstrated to provide oxidative protection for labile Trp residues in monoclonal antibodies. As a component in the formulations of protein therapeutics, NAT is sacrificially degraded; therefore understanding the identity and quantity of NAT degradants potentially formed in these drug products is essential to understanding the potential patient impact of this additive. Here we report a simple reversed phase chromatography approach that allows systematic investigation of NAT degradation in relevant formulations under stressed conditions. Screening a panel of NAT-containing samples following a variety of forced stress conditions led to a range of NAT degradation from minimal (3%) to significant (83%). NAT degradants were observed to be largely conserved between oxidative and thermal stress conditions. Online mass spectrometry and standard compound synthesis allowed for identification of the major degradants in the stressed sample panel. NAT degradation was minimal under recommended storage conditions and in relevant thermal stress conditions for a representative protein therapeutic drug product, suggesting that NAT is stable under normal manufacturing, storage, and handling conditions. This work supports the use of NAT as an antioxidant in liquid drug product formulations. Copyright © 2017. Published by Elsevier Inc.

  7. N-Acetyl-L-cysteine Effects on Multi-species Oral Biofilm Formation and Bacterial Ecology

    PubMed Central

    Rasmussen, Karin; Nikrad, Julia; Reilly, Cavan; Li, Yuping; Jones, Robert S.

    2015-01-01

    Future therapies for the treatment of dental decay have to consider the importance of preserving bacterial ecology while reducing biofilm adherence to teeth. A multi-species plaque derived (MSPD) biofilm model was used to assess how concentrations of N-acetyl-L-cysteine (0, 0.1%, 1%, 10%) affected the growth of complex oral biofilms. Biofilms were grown (n=96) for 24 hours on hydroxyapatite disks in BMM media with 0.5% sucrose. Bacterial viability and biomass formation was examined on each disk using a microtiter plate reader. In addition, fluorescence microscopy and Scanning Electron Microscopy was used to qualitatively examine the effect of NAC on bacterial biofilm aggregation, extracellular components, and bacterial morphology. The total biomass was significantly decreased after exposure of both 1% (from 0.48, with a 95% confidence interval of (0.44, 0.57) to 0.35, with confidence interval (0.31, 0.38)) and 10% NAC (0.14 with confidence interval (0.11, 0.17)). 16S rRNA amplicon sequencing analysis indicated that 1% NAC reduced biofilm adherence while preserving biofilm ecology. PMID:26518358

  8. The effect of N-acetyl-L-cysteine on the viscosity of ileal neobladder mucus.

    PubMed

    Schrier, B P; Lichtendonk, W J; Witjes, J A

    2002-05-01

    N-acetyl-L-cysteine (NAC) proved to be an effective mucolytic in pulmonary secretions. Our goal was to investigate the in vitro effect of NAC on viscosity of ileal neobladder mucus. The urine of a patient with an ileal neobladder was collected during the first 7 days postoperatively and stored in a refrigerator. After precipitation, the urine was decanted. The residue was stirred to a homogeneous suspension. To samples of 4.5 ml mucus, 0.5 ml NAC 10% was added. To the control sample, 0.5 ml water was added. The samples were incubated in a water bath at 37 degrees C for 5, 30 and 60 min. Viscosity was measured in the Bohlin VOR Rheometer. The viscosity of the ileal neobladder mucus decreased quickly after incubating with NAC 10%. Viscosity increased slightly after I h of incubation. The viscosity in the control sample was higher than in the other incubated samples. NAC was found to decrease the viscosity of ileal neobladder mucus, supporting the in vivo experience that NAC can be useful in patients with an ileal neobladder to facilitate the evacuation of mucus by decreasing viscosity.

  9. Poly-N-acetyl glucosamine fibers activate bone regeneration in a rabbit femur injury model.

    PubMed

    Muise-Helmericks, Robin C; Demcheva, Marina; Vournakis, John N; Seth, Arun

    2011-08-01

    The purpose of this study was to evaluate the ability of a membrane material, consisting only of short poly-N-acetyl glucosamine (sNAG) nanofibers, to regenerate bone tissue after implantation into circular holes in the rabbit femur. Three circular holes were created in the femurs of five male New Zealand white rabbits. The holes were ∼ 2.0 mm in diameter. Three holes in the left femur were implanted with the comparative control substance (Bone Wax; Ethicon, Inc.); three holes in the right femur were implanted with the sNAG membrane test article. Animals were killed 4 weeks after surgery, and macroscopic evaluation of the implant sites was made. Hematoxylin and eosin histology was performed on both control and test sites. All control (bone wax) sites had visible holes (defects) at the 28-day end point of the study and showed no evidence of new bone formation. All the 15 sNAG test sites were found to have new bone tissue present in the bone hole defects. Hematoxylin and eosin histology of the sNAG-treated test sites showed the presence of osteoblasts, osteocytes, and trabecula of new bone formation at the 28-day end point of the study. The sNAG membrane test material activated the regeneration of new bone tissue in a rabbit femur bone model after 28 days of implantation, whereas the control bone wax material did not.

  10. Ion-exchange equilibrium of N-acetyl-D-neuraminic acid on a strong anionic exchanger.

    PubMed

    Wu, Jinglan; Ke, Xu; Zhang, Xudong; Zhuang, Wei; Zhou, Jingwei; Ying, Hanjie

    2015-09-15

    N-acetyl-D-neuraminic acid (Neu5Ac) is a high value-added product widely applied in the food industry. A suitable equilibrium model is required for purification of Neu5Ac based on ion-exchange chromatography. Hence, the equilibrium uptake of Neu5Ac on a strong anion exchanger, AD-1 was investigated experimentally and theoretically. The uptake of Neu5Ac by the hydroxyl form of the resin occurred primarily by a stoichiometric exchange of Neu5Ac(-) and OH(-). The experimental data showed that the selectivity coefficient for the exchange of Neu5Ac(-) with OH(-) was a non-constant quantity. Subsequently, the Saunders' model, which took into account the dissociation reactions of Neu5Ac and the condition of electroneutrality, was used to correlate the Neu5Ac sorption isotherms at various solution pHs and Neu5Ac concentrations. The model provided an excellent fit to the binary exchange data for Cl(-)/OH(-) and Neu5Ac(-)/OH(-), and an approximate prediction of equilibrium in the ternary system Cl(-)/Neu5Ac(-)/OH(-). This basic information combined with the general mass transfer model could lay the foundation for the prediction of dynamic behavior of fixed bed separation process afterwards.

  11. Synthesis and characterization of a novel chitosan-N-acetyl-homocysteine thiolactone polymer using MES buffer.

    PubMed

    Ferris, C; Casas, M; Lucero, M J; de Paz, M V; Jiménez-Castellanos, M R

    2014-10-13

    We report a new "green" approach to synthesize a novel thiolated chitosan conjugate, chitosan-N-acetyl-homocysteine thiolactone (chitosan-AcHcys) using a "Good's buffers", 2-(N-morpholino)ethanesulfonic acid (MES). After that, the crosslinked Xr-chitosan-AcHcys was obtained only in the presence of air, without other reactants. The chitosan-AcHcys spectrum shows a partial incorporation of the thiolactone onto the polymer backbone. The derivative thermogravimetric analysis confirmed that chitosan-AcHcys is slightly less stable than starting chitosan; however, the peak profile is broadened which is indicative of deeper changes in the thermal degradation process. Also, aqueous dispersions with different concentrations of the crosslinked material (Xr-chitosan-AcHcys) were prepared and rheologically characterized. All aqueous dispersions are viscoelastic fluid with shear-thinning behavior. The viscosity of the dispersions (1-7% of chitosan-AcHcys) increases as a function of polymer concentration. So, we have achieved to disperse a high concentration of thiolated-chitosan derivative in water with different rheological characteristics, which could affect the drug release. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Antioxidant role of N-acetyl cysteine isomers following high dose irradiation.

    PubMed

    Neal, Rachel; Matthews, Richard H; Lutz, Paula; Ercal, Nuran

    2003-03-15

    High dose, acute radiation exposure, as in radiation accidents, induces three clinical syndromes that reflect consequences of oxidative protein, lipid, and DNA damage to tissues such as intestine, lung, and liver. In the present study, we irradiated C57BL/6 mice with 18 Gy whole-body radiation (XRT) and evaluated N-acetyl cysteine (NAC) isomers LNAC and DNAC as potential radioprotectors under conditions that would model the gastrointestinal syndrome. We focused on tissues thought not immediately involved in the gastrointestinal syndrome. Both LNAC and DNAC protected the lung and red blood cells (RBC) from glutathione (GSH) depletion following radiation exposure. However, only LNAC also supplemented the spleen GSH levels following XRT. Protection from increased malondialdehyde (MDA) levels (lung) and increased 8-hydroxy-deoxyguanosine (8-oxo-dG) presence (liver) following XRT was observed with treatment by either isomer of NAC. These results imply that either NAC isomer can act as a radioprotectant against many aspects of oxidative damage; chirality is only important for certain aspects. This pattern would be consistent with direct action of NAC in many radioprotection and repair processes, with a delimited role for NAC in GSH synthesis in some aspects of the problem.

  13. Development of antibodies for the detection of N-acetyl-glufosinate.

    PubMed

    Weller, Michael G; Diemer, Marcus; Wersching, Carola; Niessner, Reinhard; Sochor, Heinz

    2003-11-05

    Glufosinate is a widely used herbicide, which is difficult to detect by conventional analytical techniques. For many other herbicides, suitable antibodies have been raised for immunoassay development. Unfortunately, glufosinate is a very small molecule and difficult to immunize with. Thus, a derivatization-assisted immunoassay (DAIA) using the target analyte N-acetyl-glufosinate (NAG) was constructed. The activated hapten was synthesized by a new approach, using a homobifunctional cross-linker suberic acid bis(N-hydroxysuccinimide ester). The preparation of a suitable conjugate, the immunization, and the characterization of polyclonal antibodies are shown. The determination of the conjugation density (hapten density) of the immunogens was performed by four different methods (high-performance liquid chromatography with a refractive index detector, total reflection X-ray fluorescence, inductively coupled plasma mass spectrometry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry), which gave similar results. The limit of detection was 17 mug/L NAG in water for the direct competitive enzyme immunoassay. NAG is also a main metabolite of glufosinate in resistant transgenic plants. The antibodies might be useful for the selective detection of NAG in the presence of the parent compound glufosinate (cross-reactivity 0.13%) and other metabolites.

  14. A nanoparticle delivery vehicle for S-nitroso-N-acetyl cysteine: Sustained vascular response

    PubMed Central

    Nacharaju, Parimala; Tuckman-Vernon, Chaim; Maier, Keith E.; Chouake, Jason; Friedman, Adam; Cabrales, Pedro; Friedman, Joel M.

    2014-01-01

    Interest in the development of nitric oxide (NO) based therapeutics has grown exponentially owing to its well elucidated and established biological functions. In line with this surge, S-nitroso thiol (RSNO) therapeutics are also receiving more attention in recent years both as potential stable sources of NO as well as for their ability to serve as S-nitrosating agents; S-nitrosation of protein thiols is implicated in many physiological processes. We describe two hydrogel based RSNO containing nanoparticle platforms. In one platform the SNO groups are covalently attached to the particles (SNO-np) and the other contains S-nitroso-N-acetyl cysteine encapsulated within the particles (NAC-SNO-np). Both platforms function as vehicles for sustained activity as trans-S-nitrosating agents. NAC-SNO-np exhibited higher efficiency for generating GSNO from GSH and maintained higher levels of GSNO concentration for longer time (24 h) as compared to SNO-np as well as a previously characterized nitric oxide releasing platform, NO-np (nitric oxide releasing nanoparticles). In vivo, intravenous infusion of the NAC-SNO-np and NO-np resulted in sustained decreases in mean arterial pressure, though NAC-SNO-np induced longer vasodilatory effects as compared to the NO-np. Serum chemistries following infusion demonstrated no toxicity in both treatment groups. Together, these data suggest that the NAC-SNO-np represents a novel means to both study the biologic effects of nitrosothiols and effectively capitalize on its therapeutic potential. PMID:22705913

  15. Phosphoenolpyruvate-supply module in Escherichia coli improves N-acetyl-D-neuraminic acid biocatalysis.

    PubMed

    Zhu, Deqiang; Wu, Jianrong; Zhan, Xiaobei; Zhu, Li; Zheng, Zhiyong; Gao, Minjie

    2017-02-01

    N-Acetyl-D-neuraminic acid (Neu5Ac) is often synthesized from exogenous N-acetylglucosamine (GlcNAc) and excess pyruvate. We have previously constructed a recombinant Escherichia coli strain for Neu5Ac production using GlcNAc and intracellular phosphoenolpyruvate (PEP) as substrates (Zhu et al. Biotechnol Lett 38:1-9, 2016). PEP synthesis-related genes, pck and ppsA, were overexpressed within different modes to construct PEP-supply modules, and their effects on Neu5Ac production were investigated. All the PEP-supply modules enhanced Neu5Ac production. For the best module, pCDF-pck-ppsA increased Neu5Ac production to 8.6 ± 0.15 g l(-1), compared with 3.6 ± 0.15 g l(-1) of the original strain. Neu5Ac production was further increased to 15 ± 0.33 g l(-1) in a 1 l fermenter. The PEP-supply module can improve the intracellular PEP supply and enhance Neu5Ac production, which benefited industrial Neu5Ac production.

  16. N-acetyl lysyltyrosylcysteine amide inhibits myeloperoxidase, a novel tripeptide inhibitor1[S

    PubMed Central

    Zhang, Hao; Jing, Xigang; Shi, Yang; Xu, Hao; Du, Jianhai; Guan, Tongju; Weihrauch, Dorothee; Jones, Deron W.; Wang, Weiling; Gourlay, David; Oldham, Keith T.; Hillery, Cheryl A.; Pritchard, Kirkwood A.

    2013-01-01

    Myeloperoxidase (MPO) plays important roles in disease by increasing oxidative and nitrosative stress and oxidizing lipoproteins. Here we report N-acetyl lysyltyrosylcysteine amide (KYC) is an effective inhibitor of MPO activity. We show KYC inhibits MPO-mediated hypochlorous acid (HOCl) formation and nitration/oxidation of LDL. Disulfide is the major product of MPO-mediated KYC oxidation. KYC (⩽4,000 μM) does not induce cytotoxicity in bovine aortic endothelial cells (BAECs). KYC inhibits HOCl generation by phorbol myristate acetate (PMA)-stimulated neutrophils and human promyelocytic leukemia (HL-60) cells but not superoxide generation by PMA-stimulated HL-60 cells. KYC inhibits MPO-mediated HOCl formation in BAEC culture and protects BAECs from MPO-induced injury. KYC inhibits MPO-mediated lipid peroxidation of LDL whereas tyrosine (Tyr) and tryptophan (Trp) enhance oxidation. KYC is unique as its isomers do not inhibit MPO activity, or are much less effective. Ultraviolet-visible spectral studies indicate KYC binds to the active site of MPO and reacts with compounds I and II. Docking studies show the Tyr of KYC rests just above the heme of MPO. Interestingly, KYC increases MPO-dependent H2O2 consumption. These data indicate KYC is a novel and specific inhibitor of MPO activity that is nontoxic to endothelial cell cultures. Accordingly, KYC may be useful for treating MPO-mediated vascular disease. PMID:23883583

  17. Effect of N-acetyl-l-cysteine on Saccharomyces cerevisiae irradiated with gamma-rays.

    PubMed

    Kim, Jin Kyu; Park, Jiyoung; Ryu, Tae Ho; Nili, Mohammad

    2013-07-01

    Ionizing radiation (IR) induces DNA strand breaks (DSBs), base damage, inhibition of protein activity, apoptosis by reactive oxygen species (ROS). Detoxification or removal of generated ROS can reduce oxidative damage. Antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase are immediately triggered for ROS scavenging. N-acetyl-l-cysteine (NAC) having a thiol, a precursor for reduced glutathione (GSH), is known as one of the antioxidants. In this study, the effect of NAC as an antioxidant and a radioprotector was investigated on survival rate, transcriptional level of antioxidant enzymes gene, and protein level including SOD activity and intracellular GSH in yeast Saccharomyces cerevisiae W303-1A strain mutated YBP1 gene irradiated with gamma-rays. NAC did not protect the gamma-ray-induced cell death. The gene expression of antioxidant enzymes including SOD1, SOD2, GPX1, and GPX2 was induced by gamma-rays. In contrast, the pretreatment of NAC reduced the expression of these genes. NAC reduced SOD activity and intracellular GSH level in yeast. These data suggest that NAC is able to reduce radiation-induced ROS levels in vivo but does not protect yeast cells against radiation-induced death.

  18. Chitosan films with improved tensile strength and toughness from N-acetyl-cysteine mediated disulfide bonds.

    PubMed

    Miles, Kevin Barrett; Ball, Rebecca Lee; Matthew, Howard William Trevor

    2016-03-30

    To improve the mechanical properties of chitosan (Ct) materials without the use of cytotoxic crosslinkers, disulfide cross-linkable Ct was synthesized by grafting N-acetyl-cysteine (NAC) to Ct using carbodiimide chemistry. Cast films of NAC-Ct conjugates were prepared with degrees of substitution (DS) of 0%, 6%, 15%, and 20%, and the disulfide bond formation was induced by increasing the reaction media pH to 11. The tensile strength, breaking strain, elastic moduli and toughness of disulfide cross-linked polymers were analyzed by monotonic tensile testing of hydrated NAC-Ct films. Crystallinity was determined via XRD. Results demonstrated that NAC incorporation and crosslinking in chitosan produced tougher polymer films with 4-fold higher tensile strength (10 MPa) and 6-fold greater elongation (365%), but reduced crystallinity, compared to unmodified chitosan. The resilience of NAC-Ct films was evaluated by cyclic testing, and results demonstrate that increasing NAC content produced a more resilient material that dissipated less energy when deformed. These improved mechanical properties broaden chitosan's applicability towards the construction of mechanically robust implantable scaffolds for tissue regeneration.

  19. N-acetyl cysteine in clomiphene citrate resistant polycystic ovary syndrome: A review of reported outcomes.

    PubMed

    Saha, Lekha; Kaur, Sharonjeet; Saha, Pradip Kumar

    2013-07-01

    Clomiphene citrate (CC) has been the gold-standard drug for ovulation induction in polycystic ovary syndrome (PCOS), but still CC resistance is seen in approximately 15-40% in women with PCOS. N-acetyl cysteine (NAC), a safe and cheap drug available in the market many years ago as mucolytic agent, was found to have a role in infertility management. Recently, some reports discussed the possible beneficial effects of NAC on ovulation. The biological properties of the NAC make this drug a potential candidate for its use in the infertility treatment, especially in the PCOS in inducing or augmenting ovulation. An updated electronic search was performed through PUBMED, MEDLINE, and COCHRANE and focused on peer-reviewed, full text, randomized controlled trials, and observational cohort or case-control studies for role of NAC in CC-resistant PCOS. Thorough search through all the clinical studies showed mixed results. Studies with positive results showed improvement in induction of ovulation as compared to negative studies showing contrary results. More randomized clinical trials are still needed to establish its definitive role in CC-resistant PCOS.

  20. N-acetyl-L-histidine, a Prominent Biomolecule in Brain and Eye of Poikilothermic Vertebrates.

    PubMed

    Baslow, Morris H; Guilfoyle, David N

    2015-04-24

    N-acetyl-L-histidine (NAH) is a prominent biomolecule in brain, retina and lens of poikilothermic vertebrates. In fish lens, NAH exhibits an unusual compartmentalized metabolism. It is synthesized from L-histidine (His) and acetyl Co-enzyme A. However, NAH cannot be catabolized by lens cells. For its hydrolysis, NAH is exported to ocular fluid where a specific acylase cleaves His which is then actively taken up by lens and re-synthesized into NAH. This energy-dependent cycling suggested a pump mechanism operating at the lens/ocular fluid interface. Additional studies led to the hypothesis that NAH functioned as a molecular water pump (MWP) to maintain a highly dehydrated lens and avoid cataract formation. In this process, each NAH molecule released to ocular fluid down its gradient carries with it 33 molecules of bound water, effectively transporting the water against a water gradient. In ocular fluid the bound water is released for removal from the eye by the action of NAH acylase. In this paper, we demonstrate for the first time the identification of NAH in fish brain using proton magnetic resonance spectroscopy (MRS) and describe recent evidence supporting the NAH MWP hypothesis. Using MRS, we also document a phylogenetic transition in brain metabolism between poikilothermic and homeothermic vertebrates.

  1. N-Acetyl Cysteine in the Treatment of Obsessive Compulsive and Related Disorders: A Systematic Review

    PubMed Central

    Oliver, Georgina; Dean, Olivia; Camfield, David; Blair-West, Scott; Ng, Chee; Berk, Michael; Sarris, Jerome

    2015-01-01

    Objective Obsessive compulsive and related disorders are a collection of debilitating psychiatric disorders in which the role of glutamate dysfunction in the underpinning neurobiology is becoming well established. N-acetyl cysteine (NAC) is a glutamate modulator with promising therapeutic effect. This paper presents a systematic review of clinical trials and case reports exploring the use of NAC for these disorders. A further objective was to detail the methodology of current clinical trials being conducted in the area. Methods PubMed, Web of Science and Cochrane Library Database were searched for human clinical trials or case reports investigating NAC in the treatment of obsessive compulsive disorder (OCD) or obsessive compulsive related disorders. Researchers with known involvement in NAC studies were contacted for any unpublished data. Results Four clinical trials and five case reports/series were identified. Study durations were commonly 12-weeks, using 2,400–3,000 mg/day of NAC. Overall, NAC demonstrates activity in reducing the severity of symptoms, with a good tolerability profile and minimal adverse effects. Currently there are three ongoing randomized controlled trials using NAC for OCD (two adults and one pediatric), and one for excoriation. Conclusion Encouraging results have been demonstrated from the few pilot studies that have been conducted. These results are detailed, in addition to a discussion of future potential research. PMID:25912534

  2. Statistical evaluation of the isoform patterns of N-acetyl-beta-hexosaminidase from human renal cancer tissue separated by isoelectrofocusing.

    PubMed

    Borzym-Kluczyk, Malgorzata; Radziejewska, Iwona; Olszewska, Ewa; Szajda, Sławomir; Knaś, Małgorzata; Zwierz, Krzysztof

    2007-03-01

    Isoenzymes of HEX from human renal carcinoma and neighbouring macroscopically normal renal tissue can show different patterns on isoelectrofocusing gels. The aim of our work was to elaborate the method for statistical evaluation of differences. Isoenzymes of N-acetyl-beta-hexosaminidase were separated from renal (control and cancerous) tissues of 15 patients. Isoenzymes were electrofocused in Multiphor II, with ampholine pH 3.5-9.0 (2%) and then evaluated densitometrically and analysed statistically. A similar pattern in activity of isoforms of isoenzymes A and B in normal and cancerous renal tissue was observed. The proposed method of statistical evaluation of differences in isoforms of N-acetyl-beta-glucosaminidase can also be adapted to estimate the isoforms of other enzymes in different tissues.

  3. FeCl3-mediated Friedel-Crafts hydroarylation with electrophilic N-acetyl indoles for the synthesis of benzofuroindolines.

    PubMed

    Beaud, Rodolphe; Guillot, Régis; Kouklovsky, Cyrille; Vincent, Guillaume

    2012-12-07

    IRONic electrophilic indoles! The C3-regioselective hydroarylation of N-acetyl indoles with aromatic nucleophiles mediated by FeCl(3) features a rare example of the electrophilic reactivity of the indole core in a Friedel-Crafts reaction. This indole umpolung allows us straightforward access to the tetracyclic benzofuroindoline motif found in the natural product diazonamide A, which is a potent antitumor agent. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Effect of smoking on activity of N-acetyl-beta-hexosaminidase in serum and urine of renal cancer patients.

    PubMed

    Borzym-Kluczyk, Malgorzata; Radziejewska, Iwona; Zaniewska, Agnieszka; Borzym-Lewszuk, Anna; Szajda, Sławomir Dariusz; Knaś, Malgorzata; Zwierz, Krzysztof; Darewicz, Barbara

    2009-10-01

    To compare N-acetyl-beta-hexosaminidase (HEX) activity in the serum and urine of smokers as well as non-smokers with renal cancer, and healthy people. To assess hexosaminidase activity the level of p-nitrophenol released from p-nitrophenol derivatives was measured. The activity of enzyme was significantly higher in cancer group, with the highest activity in non-smokers. Cigarette smoking can inhibit, by the influence on HEX activity, catabolism of oligosaccharide chains in cancer tissues.

  5. Structural and mechanistic insights into a Bacteroides vulgatus retaining N-acetyl-β-galactosaminidase that uses neighbouring group participation.

    PubMed

    Roth, C; Petricevic, M; John, A; Goddard-Borger, E D; Davies, G J; Williams, S J

    2016-09-25

    Bacteroides vulgatus is a member of the human microbiota whose abundance is increased in patients with Crohn's disease. We show that a B. vulgatus glycoside hydrolase from the carbohydrate active enzyme family GH123, BvGH123, is an N-acetyl-β-galactosaminidase that acts with retention of stereochemistry, and, through a 3-D structure in complex with Gal-thiazoline, provide evidence in support of a neighbouring group participation mechanism.

  6. Treatment with N-acetyl-seryl-aspartyl-lysyl-proline prevents experimental autoimmune myocarditis in rats

    PubMed Central

    Nakagawa, Pablo; Liu, Yunhe; Liao, Tang-Dong; Chen, Xiaojuan; González, Germán E.; Bobbitt, Kevin R.; Smolarek, Derek; Peterson, Ed L.; Kedl, Ross; Yang, Xiao-Ping; Rhaleb, Nour-Eddine

    2012-01-01

    Myocarditis is commonly associated with cardiotropic infections and has been linked to development of autoimmunity. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a naturally occurring tetrapeptide that prevents inflammation and fibrosis in hypertension and other cardiovascular diseases; however, its effect on autoimmune-mediated cardiac diseases remains unknown. We studied the effects of Ac-SDKP in experimental autoimmune myocarditis (EAM), a model of T cell-mediated autoimmune disease. This study was conducted to test the hypothesis that Ac-SDKP prevents autoimmune myocardial injury by modulating the immune responses. Lewis rats were immunized with porcine cardiac myosin and treated with Ac-SDKP or vehicle. In EAM, Ac-SDKP prevented both systolic and diastolic cardiac dysfunction, remodeling as shown by hypertrophy and fibrosis, and cell-mediated immune responses without affecting myosin-specific autoantibodies or antigen-specific T cell responses. In addition, Ac-SDKP reduced cardiac infiltration by macrophages, dendritic cells, and T cells, pro-inflammatory cytokines [interleukin (IL)-1α, tumor necrosis factor-α, IL-2, IL-17] and chemokines (cytokine-induced neutrophil chemoattractant-1, interferon-γ-induced protein 10), cell adhesion molecules (intercellular adhesion molecule-1, L-selectin), and matrix metalloproteinases (MMP). Ac-SDKP prevents autoimmune cardiac dysfunction and remodeling without reducing the production of autoantibodies or T cell responses to cardiac myosin. The protective effects of Ac-SDKP in autoimmune myocardial injury are most likely mediated by inhibition of 1) innate and adaptive immune cell infiltration and 2) expression of proinflammatory mediators such as cytokines, chemokines, adhesion molecules, and MMPs. PMID:22923621

  7. N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils.

    PubMed

    Hasan, Md Ashraful; Ahn, Won-Gyun; Song, Dong-Keun

    2016-09-01

    N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though Ca(2+) signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ([Ca(2+)]i) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on [Ca(2+)]i in human neutrophils. We observed that NAC (1 µM ~ 1 mM) and cysteine (10 µM ~ 1 mM) increased [Ca(2+)]i in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in [Ca(2+)]i in human neutrophils was observed. In Ca(2+)-free buffer, NAC- and cysteine-induced [Ca(2+)]i increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in [Ca(2+)]i in human neutrophils occur through Ca(2+) influx. NAC- and cysteine-induced [Ca(2+)]i increase was effectively inhibited by calcium channel inhibitors SKF96365 (10 µM) and ruthenium red (20 µM). In Na(+)-free HEPES, both NAC and cysteine induced a marked increase in [Ca(2+)]i in human neutrophils, arguing against the possibility that Na(+)-dependent intracellular uptake of NAC and cysteine is necessary for their [Ca(2+)]i increasing activity. Our results show that NAC and cysteine induce [Ca(2+)]i increase through Ca(2+) influx in human neutrophils via SKF96365- and ruthenium red-dependent way.

  8. N-acetyl cysteine alleviates inflammatory reaction of oral epithelial cells to poly (methyl methacrylate) extract.

    PubMed

    Nishimiya, Hiroko; Yamada, Masahiro; Ueda, Takayuki; Sakurai, Kaoru

    2015-01-01

    The purpose of this in vitro study was to determine whether the cytotoxicity of self-curing polymethyl methacrylate (PMMA) dental resin to oral epithelial cells was eliminated by mixing the antioxidant amino acid derivative, N-acetyl cysteine (NAC) with the material. Rat and human oral epithelial cells cultured on polystyrene were incubated in culture medium with or without extract from self-curing PMMA dental resin, with or without pre-mixing with NAC. On day 1, the cultures were evaluated for cellular damage, intracellular formaldehyde invasion, cellular redox status and pro-inflammatory cytokine production. Formaldehyde content and the amount of released NAC in the extract were evaluated. Rat epithelial cells cultured with PMMA extract showed marked increases in lactate dehydrogenase (LDH) release, intracellular formaldehyde and lysosomal levels and reductions in attached cell number and the amount of E-cadherin compared with those in the culture without the extract; these adverse biological effects were alleviated or prevented by pre-mixing the resin with NAC. In human oral epithelial cells cultured with PMMA extract, the addition of NAC into the resin prevented the intracellular elevation of reactive oxygen species and the reduction in cellular glutathione levels. Human cell cultures with the extract produced higher levels of various pro-inflammatory cytokines than cultures without the extract; this was prevented by mixing the resin with NAC. The extract from PMMA pre-mixed with NAC contained a lower concentration of formaldehyde and a substantial amount of antioxidants. The cytotoxicity of self-curing PMMA dental resin to oral epithelial cells was eliminated by mixing the resin with NAC.

  9. A Preliminary Study: N-acetyl-L-cysteine Improves Semen Quality following Varicocelectomy

    PubMed Central

    Barekat, Foroogh; Tavalaee, Marziyeh; Deemeh, Mohammad Reza; Bahreinian, Mahsa; Azadi, Leila; Abbasi, Homayoun; Rozbahani, Shahla; Nasr-Esfahani, Mohammad Hossein

    2016-01-01

    Background Surgery is considered the primary treatment for male infertility from clinical varicocele. One of the main events associated with varicocele is excessive production of reactive oxygen species (ROS). N-acetyl-L-cysteine (NAC), an antioxidant that scavenges free radicals, is considered a supplement to alleviate glutathione (GSH) depletion during oxidative stress. Despite beneficial effects of NAC in other pathological events, there is no report on the effect of NAC in individuals with varicocele. Therefore, the aim of this study is to evaluate the outcome of NAC on semen quality, protamine content, DNA damage, oxidative stress and fertility following varicocelectomy. Materials and Methods This prospective clinical trial included 35 infertile men with varicocele randomly divided into control (n=20) and NAC (n=15) groups. We assessed semen parameters, protamine content [chromomycin A3 (CMA3)], DNA integrity [terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL)] and oxidative stress [2', 7'-dichlorodihydrofluorescein-diacetate (DCFH-DA)] before and three months after varicocelectomy. Results Percentage of abnormal semen parameters, protamine deficiency, DNA fragmentation and oxidative stress were significantly decreased in both groups compared to before surgery. We calculated the percentage of improvement in these parameters compared to before surgery for each group, then compared the results between the groups. Only percentage of protamine deficiency and DNA fragmentation significantly differed between the NAC and control groups. Conclusion The results of this study, for the first time, revealed that NAC improved chromatin integrity and pregnancy rate when administered as adjunct therapy post-varico- celectomy (Registeration Number: IRCT201508177223N5). PMID:27123209

  10. Determination of N-acetyl-β-hexosaminidase in serum from hemolyzed blood.

    PubMed

    Chojnowska, Sylwia; Kępka, Alina; Szajda, Sławomir Dariusz; Kołodziejczyk, Zbigniew Paweł; Zwierz, Krzysztof; Waszkiewicz, Napoleon

    2016-07-01

    Determination of lysosomal N-acetyl-β-hexosaminidase (HEX) in serum from hemolyzed blood, creates serious analytical problems, because hemoglobin absorbs light at a similar wavelength like 4-nitrophenol, which is released from artificial substrate. The objective of the work was to adapt a manual method to allow analysis of HEX in hemolyzed samples. Serums without and with hemolysis were incubated with 4-nitrophenol-N-acetylglucosamine as a substrate. Released 4-nitrophenol was determined colorimetrically. After the incubation of the serum from hemolyzed blood with substrate, hemoglobin was precipitated with trichloroacetic acid (TCA) before 4-nitrophenol determination. The mean concentration of HEX activity in non-hemolyzed and hemolyzed blood of the same patients, determined with non-modified and modified methods had no significant differences, and they are: 243.12±119.76 and 233.99±108.76pkat/mL, respectively. A coefficient of correlation between non-modified and modified methods equals the 0.98. For HEX determination with the modified method in serum from hemolyzed blood, optimal reaction time was 60min, pH of reaction mixture was 4.7, and Km was 0.11mMm. HEX determinations in the same serums from non-hemolyzed blood by the non-modified method and hemolyzed blood with the modified method, gave similar results with a 0.98 coefficient of correlation. The modified method is appropriate for HEX determination in serum from hemolyzed blood. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  11. Electrospun Microfiber Scaffolds with Anti-Inflammatory Tributanoylated N-Acetyl-d-Glucosamine Promote Cartilage Regeneration.

    PubMed

    Kim, Chaekyu; Shores, Lucas; Guo, Qiongyu; Aly, Ahmed; Jeon, Ok Hee; Kim, Do Hun; Bernstein, Nicholas; Bhattacharya, Rahul; Chae, Jemin Jeremy; Yarema, Kevin J; Elisseeff, Jennifer H

    2016-04-01

    Tissue-engineering strategies offer promising tools for repairing cartilage damage; however, these strategies suffer from limitations under pathological conditions. As a model disease for these types of nonideal systems, the inflammatory environment in an osteoarthritic (OA) joint limits the efficacy of engineered therapeutics by disrupting joint homeostasis and reducing its capacity for regeneration. In this work, we investigated a sugar-based drug candidate, a tributanoylated N-acetyl-d-glucosamine analogue, called 3,4,6-O-Bu3GlcNAc, that is known to reduce nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling in osteoarthritis. 3,4,6-O-Bu3GlcNAc not only inhibited NFκB signaling but also exerted chondrogenic and anti-inflammatory effects on chondrocytes isolated from patients with osteoarthritis. 3,4,6-O-Bu3GlcNAc also increased the expression of extracellular matrix proteins and induced cartilage tissue production in three-dimensional in vitro hydrogel culture systems. To translate these chondrogenic and anti-inflammatory properties to tissue regeneration in osteoarthritis, we implanted 3,4,6-O-Bu3GlcNAc-loaded poly(lactic-co-glycolic acid) microfiber scaffolds into rats. The drug-laden scaffolds were biocompatible, and when seeded with human OA chondrocytes, similarly promoted cartilage tissue formation. 3,4,6-O-Bu3GlcNAc combined with the appropriate structural environment could be a promising therapeutic approach for osteoarthritis.

  12. Electrospun Microfiber Scaffolds with Anti-Inflammatory Tributanoylated N-Acetyl-d-Glucosamine Promote Cartilage Regeneration

    PubMed Central

    Kim, Chaekyu; Shores, Lucas; Guo, Qiongyu; Aly, Ahmed; Jeon, Ok Hee; Kim, Do Hun; Bernstein, Nicholas; Bhattacharya, Rahul; Chae, Jemin Jeremy; Yarema, Kevin J.

    2016-01-01

    Tissue-engineering strategies offer promising tools for repairing cartilage damage; however, these strategies suffer from limitations under pathological conditions. As a model disease for these types of nonideal systems, the inflammatory environment in an osteoarthritic (OA) joint limits the efficacy of engineered therapeutics by disrupting joint homeostasis and reducing its capacity for regeneration. In this work, we investigated a sugar-based drug candidate, a tributanoylated N-acetyl-d-glucosamine analogue, called 3,4,6-O-Bu3GlcNAc, that is known to reduce nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling in osteoarthritis. 3,4,6-O-Bu3GlcNAc not only inhibited NFκB signaling but also exerted chondrogenic and anti-inflammatory effects on chondrocytes isolated from patients with osteoarthritis. 3,4,6-O-Bu3GlcNAc also increased the expression of extracellular matrix proteins and induced cartilage tissue production in three-dimensional in vitro hydrogel culture systems. To translate these chondrogenic and anti-inflammatory properties to tissue regeneration in osteoarthritis, we implanted 3,4,6-O-Bu3GlcNAc-loaded poly(lactic-co-glycolic acid) microfiber scaffolds into rats. The drug-laden scaffolds were biocompatible, and when seeded with human OA chondrocytes, similarly promoted cartilage tissue formation. 3,4,6-O-Bu3GlcNAc combined with the appropriate structural environment could be a promising therapeutic approach for osteoarthritis. PMID:27019285

  13. N-Acetyl-d-Glucosamine-Mediated Regulation of Extracellular Protease in the Entomopathogenic Fungus Beauveria bassiana

    PubMed Central

    Bidochka, Michael J.; Khachatourians, George G.

    1988-01-01

    The entomopathogenic fungus Beauveria bassiana GK2016 grown in a liquid medium incorporating gelatin as the sole carbon and nitrogen source produced an extracellular serine protease (molecular weight, 35,000; pI ca. 10). Without gelatin, B. bassiana could utilize N-acetyl-d-glucosamine (GlcNAc; 2-acetamido-2-deoxy-d-glucose) as the sole source of carbon and nitrogen, and GlcNAc availability increased the storage carbohydrate content in mycelia. Synthesis of protease was repressed in gelatin medium containing GlcNAc at levels of >1.07 μmol mg of fungal dry weight−1. At levels below this, protease synthesis was initiated; subsequently, free amino nitrogen appeared in the medium and diauxic growth was observed. Slow feeding with GlcNAc (35.34 μg ml−1 h−1) did not repress protease synthesis nor did GlcNAc accumulate in the medium above 0.5 mg ml−1. Increasing the rate of release of GlcNAc (83.51 μg ml−1 h−1) resulted in the accumulation of GlcNAc in the medium to 2.0 mg ml−1, a 45% increase in growth and a decrease in protease synthesis by about 81%. Free amino acids generated from the hydrolysis of gelatin did not repress protease synthesis. These data are interpreted in terms of known interaction of B. bassiana with insect cuticular components. We suggest that the action of extracellular chitinases synthesized by B. bassiana on insect cuticle, and pursuant release of GlcNAc, may have important consequences on the regulation of other extracellular catabolic enzymes such as the protease. Images PMID:16347772

  14. Effect of oral N-acetyl cysteine on eradication of Helicobacter pylori in patients with dyspepsia.

    PubMed

    Karbasi, A; Hossein Hosseini, S; Shohrati, M; Amini, M; Najafian, B

    2013-03-01

    Using mucolytic agents that decrease viscosity of the gastric mucous and therefore, increase the permeability of antibiotics through gastric membrane has been offered as an additive treatment to achieve a higher rate of eradication of Helicobacter pylori (H. Pylori) infection. The aim of this study was to determine the efficacy of oral N-acetyl cysteine (NAC) on eradication of H. pylori infections in patients suffering from dyspepsia. In this randomized double-blinded clinical trial, 60 H. pylori positive patients who were suffering from dyspepsia were included. They were divided into two groups. Both groups received three-drug regimen including pantoprazole 40 mg BD, ciprofloxacin 500 mg BD and bismuth subcitrate 120 mg two tablets BD. Experimental group (30 cases) received 600 mg of NAC besides three-drug regimen. Control group received placebo. The results of therapy were tested by 14C-UBT and were compared with each other two months after the first visit. H. pylori infection was eradicated in 21 (70%) and 17 (60.7%) patients in experimental and control groups, respectively (P=0.526). Regarding clinical and endoscopic variables, no significant difference was observed between the two groups except for erosive gastritis (0.041) and erosive esophagitis (0.031). Our findings offer that NAC has an additive effect on H. pylori triple therapy with pantoprazole, ciprofloxacin and bismuth subcitrate. Although NAC does not have any known activity against H. pylori, it can reduce the thickness of the mucus layer and increase the permeability of antibiotics at the site of infection. To evaluate this effect, more studies with larger sample size should be performed.

  15. Dexamethasone and N-acetyl-cysteine attenuate Pseudomonas aeruginosa-induced mucus expression in human airways.

    PubMed

    Sprenger, Lisa; Goldmann, Torsten; Vollmer, Ekkehard; Steffen, Armin; Wollenberg, Barbara; Zabel, Peter; Hauber, Hans-Peter

    2011-04-01

    Infection with Pseudomonas aeruginosa (PA) induces mucus hypersecretion in airways. Therapeutic options to attenuate excessive mucus expression are sparse. To investigate the effect of steroids and N-acetyl-cysteine (NAC) on PA-induced mucus expression. Calu-3 cells and explanted human mucosa from the upper airways were stimulated with either PA, lipopolysaccharide from alginate producing PA (smooth, sPA-LPS) or non-alginate producing PA (rough, rPA-LPS). Dexamethasone (DEX) and NAC were added in different concentrations. Expression of mucin (MUC5AC) gene and mucin protein expression was quantified using PAS (periodic acids Schiff) staining and real time PCR. PA, sPA-LPS or rPA-LPS significantly induced mucin protein and MUC5AC gene expression in Calu-3 cells and explanted mucosal tissue (P < 0.05). Both DEX and NAC significantly decreased PA-, sPA-LPS- and rPA-LPS-induced mucin protein expression both in vitro and ex vivo (P < 0.05). A significant reduction was also observed for MUC5AC gene expression with the two agents (P < 0.05) except for sPA-LPS-induced mucin gene expression in vitro (P > 0.05). Our data show that both an anti-inflammatory drug (DEX) and an anti-oxidative agent (NAC) can attenuate PA-induced mucus expression in human airways. These results support the use of steroids and NAC in clinical practice to treat PA-induced mucus hypersecretion. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils

    PubMed Central

    Hasan, Md. Ashraful; Ahn, Won-Gyun

    2016-01-01

    N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though Ca2+ signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ([Ca2+]i) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on [Ca2+]i in human neutrophils. We observed that NAC (1 µM ~ 1 mM) and cysteine (10 µM ~ 1 mM) increased [Ca2+]i in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in [Ca2+]i in human neutrophils was observed. In Ca2+-free buffer, NAC- and cysteine-induced [Ca2+]i increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in [Ca2+]i in human neutrophils occur through Ca2+ influx. NAC- and cysteine-induced [Ca2+]i increase was effectively inhibited by calcium channel inhibitors SKF96365 (10 µM) and ruthenium red (20 µM). In Na+-free HEPES, both NAC and cysteine induced a marked increase in [Ca2+]i in human neutrophils, arguing against the possibility that Na+-dependent intracellular uptake of NAC and cysteine is necessary for their [Ca2+]i increasing activity. Our results show that NAC and cysteine induce [Ca2+]i increase through Ca2+ influx in human neutrophils via SKF96365- and ruthenium red-dependent way. PMID:27610031

  17. N-Acetyl Cysteine in the Management of Rodenticide Consumption — Life Saving?

    PubMed Central

    Kenchetty, Kumar P.

    2015-01-01

    Background and Aim of Study: Rodenticide is a commonly ingested poison in India. Many rodenticides contain hepatotoxic agents and can cause acute liver failure (ALF). There is no antidote for rodenticide poison, and consumption is often fatal. The Role of N acetyl cysteine (NAC) in acetaminophen induced ALF is well established. Additionally some studies have shown that it may be useful in non-acetaminophen induced ALF also. Cases with ALF secondary to suicidal rodenticide consumption have been reported, and some reports show that NAC is beneficial in these cases. Our study was a retrospective analysis of patients admitted with rodenticide consumption, comparing outcomes in those receiving standard of care management and those who were treated with NAC also. Materials and Methods: Case sheets of all inpatients of a tertiary medical college hospital between January 2010 and December 2012 admitted with an alleged history of rodenticide consumption were surveyed and data was extracted and analysed. Statistical Analysis: Patients were analysed with respect to age, sex, mode of presentation, interval between consumption of rodenticide and starting NAC; the outcome in patients treated with acetylcysteine was compared to outcomes in those not treated with acetylcysteine Results: A total of 100 patients were studied out of which 18 died. Sixteen of the deaths were in patients who had not been treated with NAC. We found that patients who had received NAC had lower mortality, lower peak values of AST/ALT, and shorter hospital stay. Conclusion: NAC may have a role in the management of ALF associated with rodenticide consumption. PMID:25738016

  18. N-acetyl-L-cysteine potentiates depressor response to captopril and enalaprilat in SHRs.

    PubMed

    Ruiz, F J; Salom, M G; Inglés, A C; Quesada, T; Vicente, E; Carbonell, L F

    1994-09-01

    Recently, in vivo and in vitro studies have implicated nitric oxide as a mediator of the vascular effects of angiotensin-converting enzyme inhibitors (ACEIs). In the present study we hypothesized that N-acetyl-L-cysteine (NAC), by increasing the availability of reduced sulfhydryl groups, would enhance the antihypertensive response to the ACEIs captopril and enalaprilat by a mechanism dependent on nitric oxide. The experiments were performed on instrumented, indomethacin-pretreated, awake spontaneously hypertensive rats (SHRs). Thirty minutes after a bolus of captopril (10 mg/kg iv) was administered, blood pressure decreased from 167 +/- 5 to 147 +/- 6 mmHg (n = 8). The pretreatment with the donor of thiol groups NAC (300 mg/kg iv) potentiated the depressor response to captopril because blood pressure decreased from 172 +/- 3 to 139 +/- 4 mmHg (n = 6). At the dose of 60 micrograms/kg iv, the ACEI enalaprilat did not acutely modify the blood pressure of SHRs (from 172 +/- 5 to 167 +/- 4 mmHg; n = 6). However, when the SHRs were pretreated with NAC, the same dose of enalaprilat significantly reduced blood pressure from 176 +/- 5 to 151 +/- 5 mmHg (n = 6). This potentiation of the depressor response to ACEIs, due to NAC, was not observed when SHRs were pretreated with the nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 50 micrograms.kg-1.min-1 iv). The results of this study suggest that NAC, a donor of sulfhydryl groups, potentiates the antihypertensive response to captopril and enalaprilat in SHR by a nitric oxide-dependent mechanism.

  19. Widespread N-Acetyl-d-Glucosamine Uptake among Pelagic Marine Bacteria and Its Ecological Implications

    PubMed Central

    Riemann, Lasse; Azam, Farooq

    2002-01-01

    Dissolved free and combined N-acetyl-d-glucosamine (NAG) is among the largest pools of amino sugars in the ocean. NAG is a main structural component in chitin and a substantial constituent of bacterial peptidoglycan and lipopolysaccharides. We studied the distribution and kinetics of NAG uptake by the phosphoenolpyruvate:NAG phosphotransferase systems (PTS) in marine bacterial isolates and natural bacterial assemblages in near-shore waters. Of 78 bacterial isolates examined, 60 took up 3H-NAG, while 18 showed no uptake. No systematic pattern in NAG uptake capability relative to phylogenetic affiliation was found, except that all isolates within Vibrionaceae took up NAG. Among 12 isolates, some showed large differences in the relationship between polymer hydrolysis (measured as chitobiase activity) and uptake of the NAG, the hydrolysis product. Pool turnover time and estimated maximum ambient concentration of dissolved NAG in samples off Scripps Pier (La Jolla, Calif.) were 5.9 ± 3.0 days (n = 10) and 5.2 ± 0.9 nM (n = 3), respectively. Carbohydrate competition experiments indicated that glucose, glucosamine, mannose, and fructose were taken up by the same system as NAG. Sensitivity to the antibiotic and NAG structural analog streptozotocin (STZ) was developed into a culture-independent approach, which demonstrated that approximately one-third of bacteria in natural marine assemblages that were synthesizing DNA took up NAG. Isolates possessing a NAG PTS system were found to be predominantly facultative anaerobes. These results suggest the hypothesis that a substantial fraction of bacteria in natural pelagic assemblages are facultative anaerobes. The adaptive value of fermentative metabolism in the pelagic environment is potentially significant, e.g., to bacteria colonizing microenvironments such as marine snow that may experience periodic O2-limitation. PMID:12406749

  20. Widespread N-acetyl-D-glucosamine uptake among pelagic marine bacteria and its ecological implications.

    PubMed

    Riemann, Lasse; Azam, Farooq

    2002-11-01

    Dissolved free and combined N-acetyl-D-glucosamine (NAG) is among the largest pools of amino sugars in the ocean. NAG is a main structural component in chitin and a substantial constituent of bacterial peptidoglycan and lipopolysaccharides. We studied the distribution and kinetics of NAG uptake by the phosphoenolpyruvate:NAG phosphotransferase systems (PTS) in marine bacterial isolates and natural bacterial assemblages in near-shore waters. Of 78 bacterial isolates examined, 60 took up 3H-NAG, while 18 showed no uptake. No systematic pattern in NAG uptake capability relative to phylogenetic affiliation was found, except that all isolates within Vibrionaceae took up NAG. Among 12 isolates, some showed large differences in the relationship between polymer hydrolysis (measured as chitobiase activity) and uptake of the NAG, the hydrolysis product. Pool turnover time and estimated maximum ambient concentration of dissolved NAG in samples off Scripps Pier (La Jolla, Calif.) were 5.9 +/- 3.0 days (n = 10) and 5.2 +/- 0.9 nM (n = 3), respectively. Carbohydrate competition experiments indicated that glucose, glucosamine, mannose, and fructose were taken up by the same system as NAG. Sensitivity to the antibiotic and NAG structural analog streptozotocin (STZ) was developed into a culture-independent approach, which demonstrated that approximately one-third of bacteria in natural marine assemblages that were synthesizing DNA took up NAG. Isolates possessing a NAG PTS system were found to be predominantly facultative anaerobes. These results suggest the hypothesis that a substantial fraction of bacteria in natural pelagic assemblages are facultative anaerobes. The adaptive value of fermentative metabolism in the pelagic environment is potentially significant, e.g., to bacteria colonizing microenvironments such as marine snow that may experience periodic O2-limitation.

  1. Immunohistopathological changes in murine Schistosomiasis mansoni under the influence of N-acetyl-L-cysteine.

    PubMed

    de Lima Aires, André; de Azevedo Albuquerque, Mônica Camelo Pessôa; Silva, Renata Alexandre Ramos; Schirato, Giuliana Viegas; de Pontes Filho, Nicodemos Teles; de Araújo, Sidcley Bernardino; Souza, Valdênia Maria Oliveira; Costa, Vlaudia Maria Assis; Malagueño, Elizabeth

    2012-10-01

    The main pathology associated with Schistosomiasis mansoni is granulomatous inflammation that may develop into hepatosplenic disease with fibrosis and hepatoesplenomegaly. It is known that N-acetyl-L-cysteine (NAC) reduces tissue damage in chronic liver diseases owing to its anti-inflammatory, antioxidant, and detoxifying properties. In this study, we investigated the imunohistopathological changes in murine schistosomiasis mansoni under the influence of NAC, in combination with Praziquantel (PZQ) or not. Three groups of mice were formed to evaluate the effects of NAC during infection in the acute, intermediate, and chronic phases. Each group was further subdivided into four subgroups: NAC, PZQ, NAC + PZQ and control (without treatment). Oral administration of NAC (200 mg/kg/day) was carried out on the first day after infection for the acute phase and on the 45th for the intermediate and chronic phases for 59 and 45, 75 days, respectively. PZQ (100 mg/kg/day), was given orally by gavage from the 45th to 49th day after infection. Histopathological analysis of liver tissue provided evidence that combined NAC + PZQ treatment reduced the development of granulomas observed in the chronic phase. Animals treated with NAC and/or PZQ showed a reduction in the size of granulomas and all those treated with NAC exhibited a lower degree of fibrosis. In all groups, NAC decreased the synthesis of interferon-γ and nitric oxide, while increasing the levels of interleukin-10, but it did not influence the production of interleukin-4. On the whole, NAC treatment induced an immunomodulatory effect and reduced liver damage during the granulomatous inflammation in S. mansoni-infected mice.

  2. N-Acetyl-L-cysteine inhibits sulfur mustard-induced and TRPA1-dependent calcium influx.

    PubMed

    Stenger, Bernhard; Popp, Tanja; John, Harald; Siegert, Markus; Tsoutsoulopoulos, Amelie; Schmidt, Annette; Mückter, Harald; Gudermann, Thomas; Thiermann, Horst; Steinritz, Dirk

    2017-05-01

    Transient receptor potential family channels (TRPs) have been identified as relevant targets in many pharmacological as well as toxicological studies. TRP channels are ubiquitously expressed in different tissues and act among others as sensors for different external stimuli, such as mechanical stress or noxious impacts. Recent studies suggest that one member of this family, the transient receptor potential ankyrin 1 cation channel (TRPA1), is involved in pain, itch, and various diseases, suggesting TRPA1 as a potential therapeutic target. As a nociceptor, TRPA1 is mainly activated by noxious or electrophilic compounds, including alkylating substances. Previous studies already revealed an impact of 2-chloroethyl-ethyl sulfide on the ion channel TRPA1. In this study, we demonstrate that sulfur mustard (bis-(2-chloroethyl) sulfide, SM) activates the human TRPA1 (hTRPA1) in a dose-dependent manner measured by the increase in intracellular Ca(2+) concentration ([Ca(2+)]i). Besides that, SM-induced toxicity was attenuated by antioxidants. However, very little is known about the underlying mechanisms. Here, we demonstrate that N-acetyl-L-cysteine (NAC) prevents SM-induced hTRPA1-activation. HEK293-A1-E cells, overexpressing hTRPA1, show a distinct increase in [Ca(2+)]i immediately after SM exposure, whereas this increase is reduced in cells pretreated with NAC in a dose-dependent manner. Interestingly, glutathione, although being highly related to NAC, did not show an effect on hTRPA1 channel activity. Taken together, our results provide evidence that SM-dependent activation of hTRPA1 can be diminished by NAC treatment, suggesting a direct interaction of NAC and the hTRPA1 cation channel. Our previous studies already showed a correlation of hTRPA1-activation with cell damage after exposure to alkylating agents. Therefore, NAC might be a feasible approach mitigating hTRPA1-related dysregulations after exposure to SM.

  3. Can N-acetyl-L-cysteine affect zinc metabolism when used as a paracetamol antidote?

    PubMed

    Brumas, V; Hacht, B; Filella, M; Berthon, G

    1992-07-01

    N-Acetyl-L-cysteine (NAC) has long been used in the treatment of chronic lung diseases. Inhalation and oral administration of the drug are both effective in reducing mucus viscosity. In addition, NAC oral therapy allows to restore normal mucoprotein secretion in the long term. Although displaying heavy metal-complexing potential, NAC exerts no detectable influence on the metabolism of essential trace metals when used in the above context (i.e. at doses near 600 mg day-1). However, this may no longer be the case when NAC is used as an oxygen radical scavenger, like in the treatment of paracetamol poisoning. In the latter case, intravenous doses as high as 20 g day-1 are administered, which may induce excessive zinc urinary excretion. In order to allow a better appreciation of the risk of zinc depletion during NAC therapy, the present work addresses the role of this drug towards zinc metabolism at the molecular level. First, formation constants for zinc-NAC complexes have been determined under physiological conditions. Then, computer simulations for blood plasma and gastrointestinal fluid have been run to assess the influence of NAC and its metabolites (e.g. cysteine and glutathione) on zinc excretion and absorption. Blood plasma simulations reveal that NAC can effectively mobilise an important fraction of zinc into urinary excretable complexes as from concentrations of 10(-3) mol dm-3 (which corresponds to a dose of about 800 mg). This effect can still be enhanced by the action of NAC metabolites, among which cysteine is the most powerful zinc sequestering agent. In contrast, simulations relative to gastrointestinal conditions suggest that NAC should tend to increase zinc absorption, regardless of its dose.

  4. ROS inhibitor N-acetyl-L-cysteine antagonizes the activity of proteasome inhibitors.

    PubMed

    Halasi, Marianna; Wang, Ming; Chavan, Tanmay S; Gaponenko, Vadim; Hay, Nissim; Gartel, Andrei L

    2013-09-01

    NAC (N-acetyl-L-cysteine) is commonly used to identify and test ROS (reactive oxygen species) inducers, and to inhibit ROS. In the present study, we identified inhibition of proteasome inhibitors as a novel activity of NAC. Both NAC and catalase, another known scavenger of ROS, similarly inhibited ROS levels and apoptosis associated with H₂O₂. However, only NAC, and not catalase or another ROS scavenger Trolox, was able to prevent effects linked to proteasome inhibition, such as protein stabilization, apoptosis and accumulation of ubiquitin conjugates. These observations suggest that NAC has a dual activity as an inhibitor of ROS and proteasome inhibitors. Recently, NAC was used as a ROS inhibitor to functionally characterize a novel anticancer compound, piperlongumine, leading to its description as a ROS inducer. In contrast, our own experiments showed that this compound depicts features of proteasome inhibitors including suppression of FOXM1 (Forkhead box protein M1), stabilization of cellular proteins, induction of ROS-independent apoptosis and enhanced accumulation of ubiquitin conjugates. In addition, NAC, but not catalase or Trolox, interfered with the activity of piperlongumine, further supporting that piperlongumine is a proteasome inhibitor. Most importantly, we showed that NAC, but not other ROS scavengers, directly binds to proteasome inhibitors. To our knowledge, NAC is the first known compound that directly interacts with and antagonizes the activity of proteasome inhibitors. Taken together, the findings of the present study suggest that, as a result of the dual nature of NAC, data interpretation might not be straightforward when NAC is utilized as an antioxidant to demonstrate ROS involvement in drug-induced apoptosis.

  5. N-acetyl cysteine (NAC) treatment reduces mercury-induced neurotoxicity in the developing rat hippocampus

    PubMed Central

    Falluel-Morel, Anthony; Lin, Lulu; Sokolowski, Katie; McCandlish, Elizabeth; Buckley, Brian; DiCicco-Bloom, Emanuel

    2011-01-01

    Mercury is an environmental toxicant that can disrupt brain development. However, while progress has been made in defining its neurotoxic effects, we know far less about available therapies that can effectively protect brain in exposed individuals. We previously developed an animal model in which we defined the sequence of events underlying neurotoxicity: Methylmercury (MeHg) injection in postnatal rat acutely induced inhibition of mitosis and stimulated apoptosis in the hippocampus, that later resulted in intermediate term deficits in structure size and cell number. NAC is the N-acetyl derivative of L-cysteine used clinically for treatment of drug intoxication. Here, based on its known efficacy in promoting MeHg urinary excretion, we evaluated NAC for protective effects in the developing brain. In immature neurons and precursors MeHg (3µM) induced a >50% decrease in DNA synthesis at 24hr, an effect that was completely blocked by NAC co-incubation. In vivo, injection of MeHg (5µg/gbw) into 7 day-old rats induced a 22% decrease in DNA synthesis in whole hippocampus and a 4-fold increase in activated caspase-3 immunoreactive cells at 24hr, and reduced total cell numbers by 13% at 3 weeks. Treatment of MeHg exposed rats with repeated injections of NAC abolished MeHg toxicity. NAC prevented the reduction in DNA synthesis and the marked increase in caspase-3 immunoreactivity. Moreover, the intermediate term decrease in hippocampal cell number provoked by MeHg was fully blocked by NAC. Altogether, these results suggest that MeHg toxicity in the perinatal brain can be ameliorated by using NAC, opening potential avenues for therapeutic intervention. PMID:22420031

  6. Nanostructured Lipid Carrier for Topical Application of N-Acetyl Glucosamine

    PubMed Central

    Aliasgharlou, Lavin; Ghanbarzadeh, Saeed; Azimi, Hamideh; Zarrintan, Mohammad Hossein; Hamishehkar, Hamed

    2016-01-01

    Purpose: Hyperpigmentation occurs when melanin is overproduced in certain spots on the skin and is one of the most challenging skin conditions to treat. Although it is usually harmless, for cosmetic reasons, it is dreadfully bothersome to those who undergo it. It was reported that N-acetyl-glucosamine (NAGA) prevents melanin synthesis and alters the expression of numerous genes related to pigmentation. In spite of these advantages, NAGA cannot be employed in topical formulations due to its extremely polar characteristics. Nanoparticles, especially lipid-based ones, have been introduced as an efficient carrier for dermal drug delivery. Methods: The aim of the present study was to load adequate hydrophilic NAGA to the lipophilic nanostructured lipid carriers (NLCs) for potential dermal application. Methods: NAGA-loaded NLCs were formulated, using hot homogenization technique, and the characteristics of the optimized formulation were analyzed by laser light scattering, X-ray diffraction, and scanning electron microscopy methods. Loading capacity percentage and in vitro release study were carried out by applying a validated HPLC method. The optimum formulation was utilized for the in vivo skin lightening evaluations in healthy volunteers. Results: NAGA-loaded NLCs demonstrated promising results (the size of 190 nm, narrow size distribution, loading capacity of 9%, and appropriate NAGA release profile) suitable for dermal delivery. XRD results exhibited a dramatic reduction in the crystalline structure of encapsulated NAGA. Dermoscopy images indicated a considerable decline in melanin distribution pattern in the majority of the cases treated with NAGA-loaded NLCs. Conclusion: Thus, this study has opened new horizons for the potential use of lipid based nanoparticles in the managing of hyperpigmentation. PMID:28101465

  7. Urinary N-acetyl-beta-glucosaminidase as an indicator of renal dysfunction in electroplating workers.

    PubMed

    Liu, C S; Kuo, H W; Lai, J S; Lin, T I

    1998-07-01

    To investigate chromium-induced renal dysfunction in electroplating workers. A cross-sectional study was used to evaluate four biochemical markers of renal function. A total of 178 workers were divided into 3 comparable groups consisting of 34 hard-chrome plating workers, 98 nickel-chrome electroplating workers. and 46 aluminum anode-oxidation workers, who represented the reference group. Ambient and biological monitoring of urinary chromium were performed to measure exposure concentrations. Overall, urinary chromium concentrations were highest among hard-chrome plating workers (geometric mean 2.44 microg/g creatinine), followed by nickel-chrome electroplating workers (0.31 microg/g creatinine) and aluminum workers (0.09 microg/g creatinine). Airborne chromium concentrations were also highest in the hard-chrome plating area (geometric mean 4.20 microg/m3), followed by the nickel-chrome electroplating area (0.58 microg/m3) and the aluminum area (0.43 microg/m3). A positive correlation was found between urinary chromium and airborne concentrations (r=0.54, P < 0.01). Urinary concentrations of N-acetyl-beta-D-glucosaminidase (NAG) were also highest among hard-chrome plating workers (geometric mean 4.9 IU/g creatinine), followed by nickel-chrome workers (3.4 IU/g creatinine) and aluminum workers (2.9 IU/g creatinine). The prevalence of "elevated" NAG (>7 IU/g creatinine) was significantly highest among hard-chrome plating workers (23.5%), then among nickel-chrome workers (7.1%) and aluminum workers (8.7%). Differences in beta2-microglobulin, total protein, and microalbumin were not significant. The author's evidence indicates that NAG is an early indicator of renal dysfunction in hard-chrome plating workers.

  8. Supramolecular architectures of N-acetyl-L-proline monohydrate and N-benzyl-L-proline.

    PubMed

    Rajalakshmi, P; Srinivasan, N; Krishnakumar, R V; Razak, Ibrahim Abdul; Rosli, Mohd Mustaqim

    2013-11-01

    The title compounds, N-acetyl-L-proline monohydrate, C7H11NO3·H2O, (I), and N-benzyl-L-proline, C12H15NO2, (II), crystallize in the monoclinic space group P21 with Z' = 1 and Z' = 2, respectively. The conformation of C(γ) with respect to the carboxylic acid group in (I) is C(γ)-exo or UP pucker, with the pyrrolidine ring twisted, while in (II), it is C(γ)-endo or DOWN, with the pyrrolidine ring assuming an envelope conformation. The crystal packing interactions in (I) are composed of two substructures, one characterized by an R6(6)(24) motif through O-H...O hydrogen bonds and the other by an R4(4)(23) ring through C-H...O interactions. In (II), the crystal packing interactions consist of N-H...O and C-H...O hydrogen bonds. Proline (Pro) exists in its neutral form in (I) and is zwitterionic in (II). This difference in the ionization states of Pro is manifested through the absence of N-H...O and presence of O-H...O interactions in (I), and the presence of N-H...O and absence of O-H...O hydrogen bonds in (II). While C-H...O interactions are present in both (I) and (II), the geometry of the synthons formed by them and their mode of participation in intermolecular interactions is different. Though the title compounds differ significantly in terms of modifications in the Pro skeleton, the differences in their supramolecular structures may also be viewed as a result of the molecular recognition facilitated by the presence of a solvent water molecule in (I) and the zwitterionic state of the amino acid in (II).

  9. Biochemical and molecular mechanisms of N-acetyl cysteine and silymarin-mediated protection against maneb- and paraquat-induced hepatotoxicity in rats.

    PubMed

    Ahmad, Israr; Shukla, Smriti; Kumar, Ashutosh; Singh, Brajesh Kumar; Kumar, Vinod; Chauhan, Amit Kumar; Singh, Dhirendra; Pandey, Haushila Prasad; Singh, Chetna

    2013-01-25

    Oxidative stress is one of the major players in the pathogenesis of maneb (MB) and paraquat (PQ)-induced disorders. N-acetyl cysteine (NAC), a glutathione (GSH) precursor and silymarin (SIL), a naturally occurring antioxidant, encounter oxidative stress-mediated cellular damage. The present study was aimed to investigate the effects of NAC and SIL against MB and/or PQ-induced hepatotoxicity in rats. The levels of hepatotoxicity markers - alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and total bilirubin, histological changes, oxidative stress indices, phase I and phase II xenobiotic metabolizing enzymes - cytochrome P450 (CYP) and glutathione S-transferase (GST) and pro-inflammatory molecules - inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured in animals treated with MB and/or PQ in the presence or absence of NAC and SIL. MB and/or PQ augmented ALT, AST, total bilirubin, lipid peroxidation and nitrite contents and catalytic activities of superoxide dismutase and glutathione peroxidase however, the GSH content was attenuated. NAC and SIL restored the above-mentioned alterations towards basal levels but the restorations were more pronounced in SIL treated groups. Similarly, MB and/or PQ-mediated histopathological symptoms and changes in the catalytic activities/expressions of CYP1A2, CYP2E1, iNOS, TNF-α, and IL-1β were alleviated by NAC and SIL. Conversely, MB and/or PQ-induced GSTA4-4 expression/activity was further increased by NAC/SIL and glutathione reductase activity was also increased. The results obtained thus suggest that NAC and SIL protect MB and/or PQ-induced hepatotoxicity by reducing oxidative stress, inflammation and by modulating xenobitic metabolizing machinery and SIL seems to be more effective.

  10. Formation of three N-acetyl-L-cysteine monoadducts and one diadduct by the reaction of S-(1,2-dichlorovinyl)-L-cysteine sulfoxide with N-acetyl-L-cysteine at physiological conditions: chemical mechanisms and toxicological implications.

    PubMed

    Barshteyn, Nella; Elfarra, Adnan A

    2007-10-01

    Previously, our laboratory has shown that S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (DCVCS), a Michael acceptor produced by a flavin-containing monooxygenase 3 (FMO3)-mediated oxidation of S-(1,2-dichlorovinyl)-L-cysteine (DCVC), is a more potent nephrotoxicant than DCVC. In the present study, we characterized reactions of DCVCS with nucleophilic amino acids. DCVCS incubations with N-acetyl-L-cysteine (NAC) at pH 7.4 and 37 degrees C for 1 h resulted in the formation of three monoadducts and one diadduct characterized by LC/MS, 1H NMR, and 1H-detected heteronuclear single quantum correlation. The formation of all adducts (with relative ratios of 29, 31, 24, and 12%, respectively) was rapid and time-dependent; the half-lives of the two DCVCS diastereomers in the presence of NAC were 13.8 (diastereomer I) and 9.4 min (diastereomer II). Adducts 1 and 2 were determined to be diastereomers of S-[1-chloro-2-(N-acetyl-L-cystein- S-yl)vinyl]-L-cysteine sulfoxide formed by Michael addition of NAC to the terminal vinylic carbon of DCVCS followed by loss of HCl. Adduct 4 was determined to be S-[2-chloro-2-(N-acetyl-L-cystein- S-yl)vinyl]-L-cysteine sulfoxide formed from the initial Michael addition product followed by a less favorable loss of HCl and/or by a rearrangement of adduct 2 through the formation of a cyclic chloronium ion. The addition of another molecule of NAC to monoadducts 1, 2, or 4 resulted in the formation of the novel diadduct, S-[2,2-( N-acetyl-L-cystein-S-yl)vinyl]-L-cysteine sulfoxide (adduct 3), whose detection in relatively large amount suggests that DCVCS could act as a cross-linking agent. DCVCS was not reactive with N-acetyl-L-lysine or L-valinamide at similar incubation conditions. Collectively, the results suggest selective reactivity of DCVCS toward protein sulfhydryl groups. Furthermore, the cross-linking properties of DCVCS may in part explain its high nephrotoxic potency.

  11. Structural differences between two lectins from Cytisus scoparius, both specific for D-galactose and N-acetyl-D-galactosamine.

    PubMed

    Young, N M; Watson, D C; Williams, R E

    1984-08-15

    Three lectin fractions were obtained from seeds of the leguminous plant Cytisus scoparius (Scotch broom) by means of affinity chromatography on a N-acetyl-D-galactosamine medium. The first fraction, termed CSIa, was equally well inhibited in haemagglutination experiments by D-galactose and by N-acetyl-D-galactosamine and consisted of a group of isolectins formed from closely related polypeptide chains of approx. Mr 30000. The second fraction, CSIb, was closely related to CSIa in specificity, c.d. and other properties. The third fraction contained a homogeneous lectin, CSII, formed from subunits again of approx. Mr 30000. CSII was 100 times more readily inhibited by N-acetyl-D-galactosamine than by D-galactose. Despite the similarity in specificity, comparative studies of their amino acid composition, c.d. and N-terminal amino acid sequence showed that the CSIa and CSII lectins diverged considerably in structure. The lectin from Cytisus sessilifolius, specific for chitobiose, was also examined and resembled CSIa in composition and c.d. properties.

  12. Structure Analysis of the Staphylococcus aureus UDP-N-acetyl-mannosamine Dehydrogenase Cap5O Involved in Capsular Polysaccharide Biosynthesis*

    PubMed Central

    Gruszczyk, Jakub; Fleurie, Aurore; Olivares-Illana, Vanesa; Béchet, Emmanuelle; Zanella-Cleon, Isabelle; Moréra, Solange; Meyer, Philippe; Pompidor, Guillaume; Kahn, Richard; Grangeasse, Christophe; Nessler, Sylvie

    2011-01-01

    Bacterial UDP-sugar dehydrogenases are part of the biosynthesis pathway of extracellular polysaccharides. These compounds act as important virulence factors by protecting the cell from opsonophagocytosis and complement-mediated killing. In Staphylococcus aureus, the protein Cap5O catalyzes the oxidation of UDP-N-acetyl-mannosamine to UDP-N-acetyl-mannosaminuronic acid. Cap5O is crucial for the production of serotype 5 capsular polysaccharide that prevents the interaction of bacteria with both phagocytic and nonphagocytic eukaryotic cells. However, details of its catalytic mechanism remain unknown. We thus crystallized Cap5O and solved the first structure of an UDP-N-acetyl-mannosamine dehydrogenase. This study revealed that the catalytic cysteine makes a disulfide bond that has never been observed in other structurally characterized members of the NDP-sugar dehydrogenase family. Biochemical and mutagenesis experiments demonstrated that the formation of this disulfide bridge regulates the activity of Cap5O. We also identified two arginine residues essential for Cap5O activity. Previous data suggested that Cap5O is activated by tyrosine phosphorylation, so we characterized the phosphorylation site and examined the underlying regulatory mechanism. PMID:21454499

  13. Structure and Reactivity of the N-Acetyl-Cysteine Radical Cation and Anion: Does Radical Migration Occur?

    NASA Astrophysics Data System (ADS)

    Osburn, Sandra; Berden, Giel; Oomens, Jos; O'Hair, Richard A. J.; Ryzhov, Victor

    2011-10-01

    The structure and reactivity of the N-acetyl-cysteine radical cation and anion were studied using ion-molecule reactions, infrared multi-photon dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations. The radical cation was generated by first nitrosylating the thiol of N-acetyl-cysteine followed by the homolytic cleavage of the S-NO bond in the gas phase. IRMPD spectroscopy coupled with DFT calculations revealed that for the radical cation the radical migrates from its initial position on the sulfur atom to the α-carbon position, which is 2.5 kJ mol-1 lower in energy. The radical migration was confirmed by time-resolved ion-molecule reactions. These results are in contrast with our previous study on cysteine methyl ester radical cation (Osburn et al., Chem. Eur. J. 2011, 17, 873-879) and the study by Sinha et al. for cysteine radical cation ( Phys. Chem. Chem. Phys. 2010, 12, 9794-9800) where the radical was found to stay on the sulfur atom as formed. A similar approach allowed us to form a hydrogen-deficient radical anion of N-acetyl-cysteine, (M - 2H) •- . IRMPD studies and ion-molecule reactions performed on the radical anion showed that the radical remains on the sulfur, which is the initial and more stable (by 63.6 kJ mol-1) position, and does not rearrange.

  14. Hydration and N-acetyl-l-cysteine alter the microstructure of human nail and bovine hoof: implications for drug delivery.

    PubMed

    Nogueiras-Nieto, L; Gómez-Amoza, J L; Delgado-Charro, M B; Otero-Espinar, F J

    2011-12-20

    This work aimed to (a) characterize the microstructure and porosity of human nail and bovine hoof by mercury intrusion porosimetry and SEM image analysis, (b) study the effects of hydration and of N-acetyl-l-cysteine treatment on the microstructure of both membranes, and (c) determine whether the microstructural modifications were associated with changes in drug penetration measured by standard diffusion studies. Bovine hoof surface is more porous than nail surface although there were no differences between the mean surface pore sizes. Hydration and N-acetyl-l-cysteine increased the roughness and apparent surface porosity, and the porosity determined by mercury intrusion porosimetry of both membranes. Pore-Cor™ was used to generate tridimensional structures having percolation characteristics comparable to nail and hooves. The modeled structures were horizontally banded having an inner less-porous area which disappeared upon treatment. Treatment increased the predicted permeability of the simulated structures. Triamcinolone permeation increased significantly for hooves treated N-acetyl-l-cysteine, i.e., the membranes for which microstructural and permeability changes were the largest. Thus, microstructural changes determined via mercury intrusion porosimetry and subsequently modeled by Pore-Cor™ were related to drug diffusion. Further refinement of the technique will allow fast screening of penetration enhancers to be used in ungual drug delivery. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Distinct roles of N-acetyl and 5-methoxy groups in the antiproliferative and neuroprotective effects of melatonin.

    PubMed

    Letra-Vilela, Ricardo; Sánchez-Sánchez, Ana María; Rocha, Ana Maia; Martin, Vanesa; Branco-Santos, Joana; Puente-Moncada, Noelia; Santa-Marta, Mariana; Outeiro, Tiago Fleming; Antolín, Isaac; Rodriguez, Carmen; Herrera, Federico

    2016-10-15

    Melatonin (N-acetyl-5-methoxytryptamine) is a highly pleiotropic hormone with antioxidant, antiproliferative, oncolytic and neuroprotective properties. Here, we present evidence that the N-acetyl side chain plays a key role in melatonin's antiproliferative effect in HT22 and sw-1353 cells, but it does so at the expense of antioxidant and neuroprotective properties. Removal of the N-acetyl group enhances the antioxidant and neuroprotective properties of the indole, but it can lead to toxic methamphetamine-like effects in several cell lines. Inhibition of NFkB mimicked melatonin's antiproliferative and antioxidant effects, but not neuroprotection. Our results strongly suggest that neuroprotective and antiproliferative effects of melatonin rely on different parts of the molecule and are likely mediated by different mechanisms. We also predict that melatonin metabolism by target cells could determine whether melatonin inhibits cell proliferation, prevents toxicity or induces cell death (e.g. apoptosis or autophagy). These observations could have important implications for the rational use of melatonin in personalized medicine.

  16. N-acetyl-L-cysteine protects against inhaled sulfur mustard poisoning in the large swine.

    PubMed

    Jugg, B; Fairhall, S; Smith, A; Rutter, S; Mann, T; Perrott, R; Jenner, J; Salguero, J; Shute, J; Sciuto, A M

    2013-05-01

    Sulfur mustard is a blister agent that can cause death by pulmonary damage. There is currently no effective treatment. N-acetyl-L-cysteine (NAC) has mucolytic and antioxidant actions and is an important pre-cursor of cellular glutathione synthesis. These actions may have potential to reduce mustard-induced lung injury. Evaluate the effect of nebulised NAC as a post-exposure treatment for inhaled sulfur mustard in a large animal model. Fourteen anesthetized, surgically prepared pigs were exposed to sulfur mustard vapor (100 μg.kg⁻¹), 10 min) and monitored, spontaneously breathing, to 12 h. Control animals had no further intervention (n = 6). Animals in the treatment group were administered multiple inhaled doses of NAC (1 ml of 200 mg.ml⁻¹ Mucomyst™ at + 30 min, 2, 4, 6, 8, and 10 h post-exposure, n = 8). Cardiovascular and respiratory parameters were recorded. Arterial blood was collected for blood gas analysis while blood and bronchoalveolar lavage fluid were collected for hematology and inflammatory cell analysis. Urine was collected to detect a sulfur mustard breakdown product. Lung tissue samples were taken for histopathological and post-experimental analyses. Five of six sulfur mustard-exposed animals survived to 12 h. Arterial blood oxygenation (PaO₂) and saturation levels were significantly decreased at 12 h. Arterial blood carbon dioxide (PaCO₂) significantly increased, and arterial blood pH and bicarbonate (HCO₃⁻) significantly decreased at 12 h. Shunt fraction was significantly increased at 12 h. In the NAC-treated group all animals survived to 12 h (n = 8). There was significantly improved arterial blood oxygen saturation, HCO₃⁻ levels, and shunt fraction compared to those of the sulfur mustard controls. There were significantly fewer neutrophils and lower concentrations of protein in lavage compared to sulfur mustard controls. NAC's mucolytic and antioxidant properties may be responsible for the beneficial effects seen, improving

  17. Treatment of traumatic brain injury in rats with N-acetyl-seryl-aspartyl-lysyl-proline.

    PubMed

    Zhang, Yanlu; Zhang, Zheng Gang; Chopp, Michael; Meng, Yuling; Zhang, Li; Mahmood, Asim; Xiong, Ye

    2017-03-01

    OBJECTIVE The authors' previous studies have suggested that thymosin beta 4 (Tβ4), a major actin-sequestering protein, improves functional recovery after neural injury. N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is an active peptide fragment of Tβ4. Its effect as a treatment of traumatic brain injury (TBI) has not been investigated. Thus, this study was designed to determine whether AcSDKP treatment improves functional recovery in rats after TBI. METHODS Young adult male Wistar rats were randomly divided into the following groups: 1) sham group (no injury); 2) TBI + vehicle group (0.01 N acetic acid); and 3) TBI + AcSDKP (0.8 mg/kg/day). TBI was induced by controlled cortical impact over the left parietal cortex. AcSDKP or vehicle was administered subcutaneously starting 1 hour postinjury and continuously for 3 days using an osmotic minipump. Sensorimotor function and spatial learning were assessed using a modified Neurological Severity Score and Morris water maze tests, respectively. Some of the animals were euthanized 1 day after injury, and their brains were processed for measurement of fibrin accumulation and neuroinflammation signaling pathways. The remaining animals were euthanized 35 days after injury, and brain sections were processed for measurement of lesion volume, hippocampal cell loss, angiogenesis, neurogenesis, and dendritic spine remodeling. RESULTS Compared with vehicle treatment, AcSDKP treatment initiated 1 hour postinjury significantly improved sensorimotor functional recovery (Days 7-35, p < 0.05) and spatial learning (Days 33-35, p < 0.05), reduced cortical lesion volume, and hippocampal neuronal cell loss, reduced fibrin accumulation and activation of microglia/macrophages, enhanced angiogenesis and neurogenesis, and increased the number of dendritic spines in the injured brain (p < 0.05). AcSDKP treatment also significantly inhibited the transforming growth factor-β1/nuclear factor-κB signaling pathway. CONCLUSIONS AcSDKP treatment

  18. N-Acetyl-β-D-glucosaminidase activity in feral Carcinus maenas exposed to cadmium.

    PubMed

    Mesquita, Sofia Raquel; Ergen, Şeyda Fikirdeşici; Rodrigues, Aurélie Pinto; Oliva-Teles, M Teresa; Delerue-Matos, Cristina; Guimarães, Laura

    2015-02-01

    Cadmium is a priority hazardous substance, persistent in the aquatic environment, with the capacity to interfere with crustacean moulting. Moulting is a vital process dictating crustacean growth, reproduction and metamorphosis. However, for many organisms, moult disruption is difficult to evaluate in the short term, what limits its inclusion in monitoring programmes. N-acetyl-β-D-glucosaminidase (NAGase) is an enzyme acting in the final steps of the endocrine-regulated moulting cascade, allowing for the cast off of the old exoskeleton, with potential interest as a biomarker of moult disruption. This study investigated responses to waterborne cadmium of NAGase activity of Carcinus maenas originating from estuaries with different histories of anthropogenic contamination: a low impacted and a moderately polluted one. Crabs from both sites were individually exposed for seven days to cadmium concentrations ranging from 1.3 to 2000 μg/L. At the end of the assays, NAGase activity was assessed in the epidermis and digestive gland. Detoxification, antioxidant, energy production, and oxidative stress biomarkers implicated in cadmium metabolism and tolerance were also assessed to better understand differential NAGase responses: activity of glutathione S-transferases (GST), glutathione peroxidase (GPx) glutathione reductase (GR), levels of total glutathiones (TG), lipid peroxidation (LPO), lactate dehydrogenase (LDH), and NADP(+)-dependent isocitrate dehydrogenase (IDH). Animals from the moderately polluted estuary had lower NAGase activity both in the epidermis and digestive gland than in the low impacted site. NAGase activity in the epidermis and digestive gland of C. maenas from both estuaries was sensitive to cadmium exposure suggesting its usefulness for inclusion in monitoring programmes. However, in the digestive gland NAGase inhibition was found in crabs from the less impacted site but not in those from the moderately contaminated one. Altered glutathione levels were

  19. Crystal structure of product-bound complex of UDP-N-acetyl-D-mannosamine dehydrogenase from Pyrococcus horikoshii OT3

    SciTech Connect

    Pampa, K.J.; Lokanath, N.K.; Girish, T.U.; Kunishima, N.; Rai, V.R.

    2014-10-24

    Highlights: • Determined the structure of UDP-D-ManNAcADH to a resolution of 1.55 Å. • First complex structure of PhUDP-D-ManNAcADH with UDP-D-ManMAcA. • The monomeric structure consists of three distinct domains. • Cys258 acting as catalytic nucleophilic and Lys204 acts as acid/base catalyst. • Oligomeric state plays an important role for the catalytic function. - Abstract: UDP-N-acetyl-D-mannosamine dehydrogenase (UDP-D-ManNAcDH) belongs to UDP-glucose/GDP-mannose dehydrogenase family and catalyzes Uridine-diphospho-N-acetyl-D-mannosamine (UDP-D-ManNAc) to Uridine-diphospho-N-acetyl-D-mannosaminuronic acid (UDP-D-ManNAcA) through twofold oxidation of NAD{sup +}. In order to reveal the structural features of the Pyrococcus horikoshii UDP-D-ManNAcADH, we have determined the crystal structure of the product-bound enzyme by X-ray diffraction to resolution of 1.55 Å. The protomer folds into three distinct domains; nucleotide binding domain (NBD), substrate binding domain (SBD) and oligomerization domain (OD, involved in the dimerization). The clear electron density of the UDP-D-ManNAcA is observed and the residues binding are identified for the first time. Crystal structures reveal a tight dimeric polymer chains with product-bound in all the structures. The catalytic residues Cys258 and Lys204 are conserved. The Cys258 acts as catalytic nucleophile and Lys204 as acid/base catalyst. The product is directly interacts with residues Arg211, Thr249, Arg244, Gly255, Arg289, Lys319 and Arg398. In addition, the structural parameters responsible for thermostability and oligomerization of the three dimensional structure are analyzed.

  20. Isoenzymes A and B of N-acetyl-beta-D-hexosaminidase in serum and urine of patients with pancreatic cancer.

    PubMed

    Szajda, Slawomir Dariusz; Snarska, Jadwiga; Jankowska, Anna; Puchalski, Zbigniew; Zwierz, Krzysztof

    2008-01-01

    Adenocarcinoma is the most frequent malignant tumor of the pancreas. Biochemical diagnostics of pancreatic adenocarcinoma is based on determination of carcinoma antigen (CA 19-9) in the blood. Determination of N-acetyl-beta-hexosaminidase (HEX) in the serum and urine was used in diagnosis of renal and gastric cancers. Therefore the aim of our research was to estimate N-acetyl-beta-hexosaminidase (HEX) and its isoenzymes (HEX A and HEX B) in the serum and urine as potential markers of pancreatic cancer. Serum and urine samples were collected from 15 patients with adenocarcinoma of the pancreas and 15 healthy persons. The activity of N-acetyl-beta-hexosaminidase and its isoenzymes (A and B) was determined by a colorimetric method of Zwierz et al. Absorbancy of the yellow product of the colorimetric reaction was determined on the microplate reader EL(x)800 produced by BIO-TEK. The concentration of HEX, HEX A and B was expressed in pKat/mL, and the specific activity in pKat/mg of protein. Protein concentration was determined in the serum by the biuret and in the urine by the Lowry method, respectively, and expressed in mg/mL. The concentration and specific activity of HEX and its isoenzyme A were significantly higher in the serum and urine of pancreatic cancer patients in comparison with the concentration and specific activity in the serum and urine of healthy people. The results suggest that the activity of HEX and its isoenzyme A determined in the serum and urine can be used as a potential marker of pancreatic adenocarcinoma.

  1. Release and utilization of N-acetyl-D-glucosamine from human milk oligosaccharides by Bifidobacterium longum subsp. infantis.

    PubMed

    Garrido, Daniel; Ruiz-Moyano, Santiago; Mills, David A

    2012-08-01

    Human milk contains high amounts of complex oligosaccharides, which can be utilized especially by Bifidobacterium species in the infant gut as a carbon and energy source. N-acetyl-D-glucosamine is a building block of these oligosaccharides, and molecular details on the release and utilization of this monosaccharide are not fully understood. In this work we have studied some of the enzymatic properties of three N-acetyl-β-D-hexosaminidases encoded by the genome of the intestinal isolate Bifidobacterium longum subsp. infantis ATCC 15697 and the gene expression of the corresponding genes during bacterial growth on human milk oligosaccharides. These enzymes belong to the glycosyl hydrolase family 20, with several homologs in bifidobacteria. Their optimum pH was 5.0 and optimum temperature was 37 °C. The three enzymes were active on the GlcNAcβ1-3 linkage found in lacto-N-tetraose, the most abundant human milk oligosaccharide. Blon_0459 and Blon_0732, but not Blon_2355, cleaved branched GlcNAcβ1-6 linkages found in lacto-N-hexaose, another oligosaccharide abundant in breast milk. Bifidobacterium infantis N-acetyl-β-D-hexosaminidases were induced during early growth in vitro on human milk oligosaccharides, and also during growth on lacto-N-tetraose or lacto-N-neotetraose. The up-regulation of enzymes that convert this monosaccharide into UDP-N-acetylglucosamine by human milk oligosaccharides suggested that this activated sugar is used in peptidoglycan biosynthesis. These results emphasize the complexity of human milk oligosaccharide consumption by this infant intestinal isolate, and provide new clues into this process.

  2. Recognition of chitooligosaccharides and their N-acetyl groups by putative subsites of chitin deacetylase from a deuteromycete, Colletotrichum lindemuthianum.

    PubMed

    Tokuyasu, K; Mitsutomi, M; Yamaguchi, I; Hayashi, K; Mori, Y

    2000-08-01

    The reaction pattern of an extracellular chitin deacetylase from a Deuteromycete, Colletotrichum lindemuthianum ATCC 56676, was investigated by use of chitooligosaccharides [(GlcNAc)(n)(), n = 3-6] and partially N-deacetylated chitooligosaccharides as substrates. When 0.5% of (GlcNAc)(n)() was deacetylated, the corresponding monodeacetylated products were initially detected without any processivity, suggesting the involvement of a multiple-chain mechanism for the deacetylation reaction. The structural analysis of these first-step products indicated that the chitin deacetylase strongly recognizes a sequence of four N-acetyl-D-glucosamine (GlcNAc) residues of the substrate (the subsites for the four GlcNAc residues are defined as -2, -1, 0, and +1, respectively, from the nonreducing end to the reducing end), and the N-acetyl group in the GlcNAc residue positioned at subsite 0 is exclusively deacetylated. When substrates of a low concentration (100 microM) were deacetylated, the initial deacetylation rate for (GlcNAc)(4) was comparable to that of (GlcNAc)(5), while deacetylation of (GlcNAc)(3) could not be detected. Reaction rate analyses of partially N-deacetylated chitooligosaccharides suggested that subsite -2 strongly recognizes the N-acetyl group of the GlcNAc residue of the substrate, while the deacetylation rate was not affected when either subsite -1 or +1 was occupied with a D-glucosamine residue instead of GlcNAc residue. Thus, the reaction pattern of the chitin deacetylase is completely distinct from that of a Zygomycete, Mucor rouxii, which produces a chitin deacetylase for accumulation of chitosan in its cell wall.

  3. Inhibition by acetaminophen of neoplastic initiation elicited in rat liver by the DNA-reactive hepatocarcinogen N-acetyl-2-aminofluorene.

    PubMed

    Williams, Gary M; Iatropoulos, Michael J; Jeffrey, Alan M; Duan, Jian-Dong; Perrone, Carmen E

    2007-12-01

    Acetaminophen, a monocyclic phenolic compound and analgesic, when fed at 8900 p.p.m. in the diet, was reported to inhibit the hepatocarcinogenicity in rats of the aromatic amine proximate carcinogen N-hydroxy-N-acetyl-2-aminofluorene. To elucidate the mechanism(s) of this anticarcinogenicity, the present study examined whether acetaminophen at lower doses has the ability to inhibit the initiating effects in the rat liver of the precursor hepatocarcinogen N-acetyl-2-aminofluorene. Male F344 rats were allocated to six groups, which were maintained under reverse light cycle conditions to assure acetaminophen ingestion at the time of N-acetyl-2-aminofluorene administration during the dark phase, which was imposed from 07.00 to 19.00 h. Group 1 served as vehicle control (0.5% carboxymethylcellulose) for N-acetyl-2-aminofluorene, which was administered intragastrically 3 days per week at 2.6 mg/kg for 8 weeks (group 4) to achieve initiation. Acetaminophen was given in the diet either alone at 2400 or 4800 p.p.m. for 9 weeks (groups 2 and 3), or with N-acetyl-2-aminofluorene (groups 5 and 6), starting 1 week before N-acetyl-2-aminofluorene administration. Acetaminophen blood levels were about 1 and 4 microg/ml at the two dietary concentrations. N-acetyl-2-aminofluorene induced hepatocellular preneoplastic lesions measured as hepatocellular altered foci expressing glutathione S-transferase-P, reflecting initiation. Induced foci were reduced with administration of both concentrations of acetaminophen. Acetaminophen by itself produced no DNA adducts nor did it alter the high formation of N-acetyl-2-aminofluorene-DNA adducts, about 200 in 10 nucleotides, measured by nucleotide postlabeling. Acetaminophen did not affect background liver cell proliferation, but significantly reduced N-acetyl-2-aminofluorene-induced increased proliferation measured by proliferating cell nuclear antigen immunostaining. Thus, acetaminophen effectively protected hepatocytes from the initiating

  4. Effects of bucillamine and N-acetyl-l-cysteine on cytokine production and collagen-induced arthritis (CIA)

    PubMed Central

    Tsuji, F; Miyake, Y; Aono, H; Kawashima, Y; Mita, S

    1999-01-01

    We investigated the effects of bucillamine and N-acetyl-l-cysteine (NAC) on cytokine production and CIA. Bucillamine and NAC inhibited NF-κB activation and tumour necrosis factor-alpha (TNF-α) mRNA expression in human monocytic leukaemia cell line THP-1, and cytokine production from monocyte cell lines at concentrations >10−3 m. They also inhibited cytokine production and CIA in mice at a dose of 500 mg/kg. These results suggest that NF-κB inhibitors such as bucillamine and NAC may inhibit cytokine-related diseases, including arthritis. PMID:9933417

  5. Qualitative Differences in the N-Acetyl-D-galactosaminyltransferases Produced by Human A1 and A2 Genes

    PubMed Central

    Schachter, H.; Michaels, M. A.; Tilley, Christine A.; Crookston, Marie C.; Crookston, J. H.

    1973-01-01

    This study describes the kinetic properties of N-acetyl-D-galactosaminyltransferase in serum from subjects with blood groups A1 and A2. When the A1 and A2 enzymes were compared, with lacto-N-fucopentaose I and 2′-fucosyllactose as acceptors, the enzymes differed in their cation requirements, pH optima, and Km values. The two acceptors competed for the same transferase. Mixing experiments showed that the lower activity of the A2 enzyme could not be attributed to a modifier or inhibitor in serum. It was concluded that the A1 and A2 enzymes differ qualitatively. PMID:4509655

  6. Impact of 30-Day Oral Dosing With N-Acetyl-L-Cysteine on Sprague-Dawley Rat Physiology

    DTIC Science & Technology

    2004-07-01

    A number of studies have demonstrated a protective effect associated with N- acetyl -L- cysteine ( NAC ) against toxic chemical exposure. However, the...impact of long-term oral dosing on tssue pathology has not been determined. In this study, we assessed the impact of long-term oral NAC administration on...SD rats (10 male, 10 female), 8 weeks of age, were dosed daily by oral gavage with deionized H2O (negative controls) or NAC solution at a rate of 600

  7. N-Acetyl-D-Mannosamine Treatment Alleviates Age-Related Decline in Place-Learning Ability in Dogs

    PubMed Central

    NAGASAWA, Miho; SHIMOZAWA, Aki; MOGI, Kazutaka; KIKUSUI, Takefumi

    2014-01-01

    ABSTRACT This study aimed to investigate the therapeutic effects of N-acetyl-D-mannosamine (ManNAc) on age-related cognitive dysfunction in dogs. ManNAc was administered to 5 dogs with low cognitive levels for 2 months, and the cognitive ability and active-resting cycle were periodically assessed for improvement. ManNAc treatment significantly reduced the number of error trials in the place-learning test, especially in the first month of administration. Three ManNAc-treated dogs also showed improvement in the active-resting cycle. In conclusion, ManNAc treatment appears to alleviate age-related cognitive dysfunction. PMID:24430654

  8. Modification and periplasmic translocation of the biofilm exopolysaccharide poly-β-1,6-N-acetyl-d-glucosamine

    PubMed Central

    Little, Dustin J.; Li, Grace; Ing, Christopher; DiFrancesco, Benjamin R.; Bamford, Natalie C.; Robinson, Howard; Nitz, Mark; Pomès, Régis; Howell, P. Lynne

    2014-01-01

    Poly-β-1,6-N-acetyl-d-glucosamine (PNAG) is an exopolysaccharide produced by a wide variety of medically important bacteria. Polyglucosamine subunit B (PgaB) is responsible for the de–N-acetylation of PNAG, a process required for polymer export and biofilm formation. PgaB is located in the periplasm and likely bridges the inner membrane synthesis and outer membrane export machinery. Here, we present structural, functional, and molecular simulation data that suggest PgaB associates with PNAG continuously during periplasmic transport. We show that the association of PgaB’s N- and C-terminal domains forms a cleft required for the binding and de–N-acetylation of PNAG. Molecular dynamics (MD) simulations of PgaB show a binding preference for N-acetylglucosamine (GlcNAc) to the N-terminal domain and glucosammonium to the C-terminal domain. Continuous ligand binding density is observed that extends around PgaB from the N-terminal domain active site to an electronegative groove on the C-terminal domain that would allow for a processive mechanism. PgaB’s C-terminal domain (PgaB310–672) directly binds PNAG oligomers with dissociation constants of ∼1–3 mM, and the structures of PgaB310–672 in complex with β-1,6-(GlcNAc)6, GlcNAc, and glucosamine reveal a unique binding mode suitable for interaction with de–N-acetylated PNAG (dPNAG). Furthermore, PgaB310–672 contains a β-hairpin loop (βHL) important for binding PNAG that was disordered in previous PgaB42–655 structures and is highly dynamic in the MD simulations. We propose that conformational changes in PgaB310–672 mediated by the βHL on binding of PNAG/dPNAG play an important role in the targeting of the polymer for export and its release. PMID:24994902

  9. Simultaneous measurement of N-Acetyl-S-(2-cyanoethyl)-cysteine and N-acetyl-S-(2-hydroxyethyl)-cysteine in human urine by liquid chromatography-tandem mass spectrometry.

    PubMed

    Xiaotao, Zhang; Hongwei, Hou; Wei, Xiong; Qingyuan, Hu

    2014-08-01

    Acrylonitrile, possibly carcinogenic to humans, is mainly present in tobacco smoke and undergoes metabolism to form N-acetyl-S-(2-cyanoethyl)-cysteine (CEMA) and N-acetyl-S-(2-hydroxyethyl)-cysteine (HEMA). A method based on the direct dilution to simultaneously identify and quantify CEMA and HEMA in human urine by rapid resolution liquid chromatography-electrospray ionization tandem mass spectrometry (RRLC-MS-MS) was validated for assessing smoking-related acrylonitrile exposure. The recovery rates of the whole analytical procedure were 98.2-106.0% and 97.1-112.7% for HEMA and CEMA, respectively. The linear range of standard solutions was 0.5-100.0 ng/mL for CEMA and was 0.2-40.0 ng/mL for HEMA. RRLC using a small particle size column was combined with a tandem mass spectrometry system, which lowered the detection limit of analytes, reduced the ion suppression of mass and shortened the analysis time. The proposed method was successfully applied for the analysis of 126 urine samples from smokers and nonsmokers.

  10. Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A & B in workers exposed to cadmium at cadmium plating

    PubMed Central

    Kalahasthi, Ravi Babu; Rajmohan, HR; Rajan, BK; Kumar M, Karuna

    2007-01-01

    Objective The present study was carried out to determine the effect of cadmium exposure on Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B in workers exposed at cadmium plating. Methods 50 subjects using cadmium during cadmium plating formed the study group. An equal number of age-sex matched subjects working in administrative section formed the control group. Urinary cadmium levels were determined by using a flameless atomic absorption spectrophotometer. Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B were determined by using spectrophotmetric method. Results A significant increase of urinary total N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B profiles were noted in study as compared to controls. The levels of urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B profiles were positively and significantly correlated with cadmium levels in urine. Multiple regression analysis was used to assess the effect of urinary cadmium or life style confounding factors (age, BMI, smoking and alcohol consumption) on urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B. The analysis showed that the study subjects who had urine cadmium levels greater than 5 μg/g of creatinine, work duration >15 years, smoking and body mass index variables were significantly associated with urinary total N-acetyl-beta -D-glucosaminidase but not on isoenzymes A&B. Conclusion The results presented in this study shows that the increased levels of urinary N-acetyl-beta -D-glucosaminidase observed in cadmium-exposed workers could be used as biomarkers for suggesting preventive measure. PMID:17659077

  11. Improved expression, purification and crystallization of a putative N-acetyl-γ-glutamyl-phosphate reductase from rice (Oryza sativa)

    SciTech Connect

    Miura-Ohnuma, Jun; Nonaka, Tsuyoshi; Katoh, Shizue; Murata, Katsuyoshi; Kita, Akiko; Miki, Kunio

    2005-12-01

    Crystals of OsAGPR were obtained using the sitting-drop vapour-diffusion method at 293 K and diffract X-rays to at least 1.8 Å resolution. They belong to the hexagonal space group P6{sub 1}, with unit-cell parameters a = 86.11, c = 316.3 Å. N-Acetyl-γ-glutamyl-phosphate reductase (AGPR) catalyzes the third step in an eight-step arginine-biosynthetic pathway that starts with glutamate. This enzyme converts N-acetyl-γ-glutamyl phosphate to N-acetylglutamate-γ-semialdehyde by an NADPH-dependent reductive dephosphorylation. AGPR from Oryza sativa (OsAGPR) was expressed in Escherichia coli at 291 K as a soluble fusion protein with an upstream thioredoxin-hexahistidine [Trx-(His){sub 6}] extension. OsAGPR(Ala50–Pro366) was purified and crystals were obtained using the sitting-drop vapour-diffusion method at 293 K and diffract X-rays to at least 1.8 Å resolution. They belong to the hexagonal space group P6{sub 1}, with unit-cell parameters a = 86.11, c = 316.3 Å.

  12. Affinity Separation of Lectins Using Porous Membranes Immobilized with Glycopolymer Brushes Containing Mannose or N-Acetyl-d-Glucosamine

    PubMed Central

    Ogata, Yutaro; Seto, Hirokazu; Murakami, Tatsuya; Hoshino, Yu; Miura, Yoshiko

    2013-01-01

    Porous membranes with glycopolymer brushes were prepared as biomaterials for affinity separation. Glycopolymer brushes contained acrylic acid and D-mannose or N-acetyl-D-glucosamine, and were formed on substrates by surface-initiated atom transfer radical polymerization. The presence of glycopolymer brush was confirmed by X-ray photoelectron spectroscopy, contact angle, and ellipsometry measurements. The interaction between lectin and the glycopolymer immobilized on glass slides was confirmed using fluorescent-labeled proteins. Glycopolymer-immobilized surfaces exhibited specific adsorption of the corresponding lectin, compared with bovine serum albumin. Lectins were continuously rejected by the glycopolymer-immobilized membranes. When the protein solution was permeated through the glycopolymer-immobilized membrane, bovine serum albumin was not adsorbed on the membrane surface. In contrast, concanavalin A and wheat germ agglutinin were rejected by membranes incorporating D-mannose or N-acetyl-D-glucosamine, respectively. The amounts of adsorbed concanavalin A and wheat germ agglutinin was increased five- and two-fold that of adsorbed bovine serum albumin, respectively. PMID:24956944

  13. Evaluation of fluoropyruvate as nucleophile in reactions catalysed by N-acetyl neuraminic acid lyase variants: scope, limitations and stereoselectivity.

    PubMed

    Stockwell, Jennifer; Daniels, Adam D; Windle, Claire L; Harman, Thomas A; Woodhall, Thomas; Lebl, Tomas; Trinh, Chi H; Mulholland, Keith; Pearson, Arwen R; Berry, Alan; Nelson, Adam

    2016-01-07

    The catalysis of reactions involving fluoropyruvate as donor by N-acetyl neuraminic acid lyase (NAL) variants was investigated. Under kinetic control, the wild-type enzyme catalysed the reaction between fluoropyruvate and N-acetyl mannosamine to give a 90 : 10 ratio of the (3R,4R)- and (3S,4R)-configured products; after extended reaction times, equilibration occurred to give a 30 : 70 mixture of these products. The efficiency and stereoselectivity of reactions of a range of substrates catalysed by the E192N, E192N/T167V/S208V and E192N/T167G NAL variants were also studied. Using fluoropyruvate and (2R,3S)- or (2S,3R)-2,3-dihydroxy-4-oxo-N,N-dipropylbutanamide as substrates, it was possible to obtain three of the four possible diastereomeric products; for each product, the ratio of anomeric and pyranose/furanose forms was determined. The crystal structure of S. aureus NAL in complex with fluoropyruvate was determined, assisting rationalisation of the stereochemical outcome of C-C bond formation.

  14. Hydrosoluble 50% N-acetylation-thiolated chitosan complex with cobalt as a pH-responsive renal fibrosis targeting drugs.

    PubMed

    Li, Min; Tan, Lishan; Tang, Liangfeng; Li, Aiqing; Hu, Jianqiang

    2016-07-01

    About 50% N-acetylation-thiolated chitosan possessing good water solubility was modified from commercial low-molecular-weight chitosan. Chitosan performed obvious target toward renal tubular epithelial cells, and bivalent cobalt ions improved the renal fibrosis inflammation significantly. There were many complexation sites on chitosan after being modified with sulfydryl. So sulfydryl played a role of connecting bridge between chitosan and cobalt ions. Then, this N-acetylation-thiolated chitosan cobalt (NTCC) nanocomplex was designed. The nanocomplex showed excellent stability under normal physiological conditions, and cobalt would be released from the biomaterials in acidic environment. As it was affected by inflammation, the pH in renal fibrosis lesion region was acidic. So there was a specific drug release process happening in lesion region. And drug release efficiency was determined by acidity, which demonstrated that lower the acidity, the faster and more the cobalt ion release. When this nanocomplex was intraperitoneally injected into ureter-obstructed mice, obvious attenuation of fibrotic progression was shown. It was demonstrated that NTCC exhibited special renal-targeting capacity and could be chosen as drug for treating renal fibrosis.

  15. Modulatory effects of curcumin and green tea extract against experimentally induced pulmonary fibrosis: a comparison with N-acetyl cysteine.

    PubMed

    Hamdy, Mohammed Ahmed; El-Maraghy, Shohda A; Kortam, Mona Abd El Aziz

    2012-11-01

    The study was aimed to investigate the protective effect of green tea extract (GTE), curcumin, and N-acetyl cysteine (NAC) on experimentally induced pulmonary fibrosis. Curcumin (200 mg/kg b.w), GTE (150 mg/kg b.w), and NAC (490 mg/kg b.w) were administered orally for 14 days with concomitant administration of cyclophosphamide (CP). Lung fibrosis was assessed by measuring hydroxyproline and elastin levels and confirmed by histopathological examination. Oxidative stress was also observed in the CP group. Lung myeloperoxidase activity was significantly decreased in animals of the CP group. N-acetyl-β-d-glucosaminidase, leukotriene C₄, and protein were increased in bronchoalveolar lavage fluid (BALF). Transforming growth factor-β, interleukin -1β, and histamine were increased in both serum and BALF. All modulators markedly attenuated the altered biochemical parameters as compared to CP-treated rats. These results suggest the possibility of using these treatments as protective agents with chemotherapy and as protective agents for lung fibrosis.

  16. Identification of an extended N-acetylated sequence adjacent to the protein-linkage region of fibroblast heparan sulphate.

    PubMed Central

    Lyon, M; Steward, W P; Hampson, I N; Gallagher, J T

    1987-01-01

    The distribution of N-sulphate groups within fibroblast heparan sulphate chains was investigated. The detergent-extractable heparan sulphate proteoglycan from adult human skin fibroblasts, radiolabelled with [3H]glucosamine and [35S]sulphate, was coupled to CNBr-activated Sepharose 4B. After partial depolymerization of the heparan sulphate with nitrous acid, the remaining Sepharose-bound fragments were removed by treatment with alkali. These fragments, of various sizes, but all containing an intact reducing xylose residue, were fractionated on Sephacryl S-300 and the distribution of the 3H and 35S radiolabels was analysed. A decreased degree of sulphation was observed towards the reducing termini of the chains. After complete nitrous acid hydrolysis of the Sepharose-bound proteoglycan, analysis of the proximity of N-sulphation to the reducing end revealed the existence of an extended N-acetylated sequence directly adjacent to the protein-linkage sequence. The size of this N-acetylated domain was estimated by gel filtration to be approximately eight disaccharide units. This domain appears to be highly conserved, being present in virtually all the chains derived from this proteoglycan, implying the existence of a mechanism capable of generating such a non-random sequence during the post-polymeric modification of heparan sulphate. Comparison with the corresponding situation in heparin suggests that different mechanisms regulate polymer N-sulphation in the vicinity of the protein-linkage region of these chemically related glycosaminoglycans. PMID:2954540

  17. Identifying dominant conformations of N-acetyl-L-cysteine methyl ester and N-acetyl-L-cysteine in water: VCD signatures of the amide I and the Cdbnd O stretching bands

    NASA Astrophysics Data System (ADS)

    Poopari, Mohammad Reza; Dezhahang, Zahra; Xu, Yunjie

    2015-02-01

    Infrared (IR) and vibrational circular dichroism (VCD) spectra of N-Acetyl-L-Cysteine Methyl Ester (NALCME) and N-Acetyl-L-Cysteine (NALC) in D2O under different pHs were measured. We focus on the VCD signatures of the amide I and the Cdbnd O stretching spectral signatures of the neutral NALCME and NALC species and the related ones of the deprotonated NALC species in the region of 1800-1500 cm-1. A sign inversion is observed for the amide I VCD band going from the neutral NALCME and NALC to the deprotonated NALC species. Density functional theory (DFT) calculations were carried out to search for the possible conformations of these three species and to simulate their IR and VCD spectra at the B3LYP/aug-cc-pVTZ level in the gas phase and with the polarization continuum model of water solvent. The most stable conformations found for neutral NALCME and NALC exhibit drastically difference VCD patterns, whereas those of deprotonated NALC show similar patterns. We establish an empirical structural-spectral relationship where the aforementioned VCD signatures can be used as spectral markers to identify dominant conformations of these two amino acid derivatives under different pHs. It is recognized that the dominant conformers identified using the VCD spectral markers differ from those based on the relative DFT energies for neutral NALCME and NALC. The influence of solvent on both the conformational geometries and their relative stabilities is discussed. The aforementioned discrepancy can be attributed to the explicit solute-solvent hydrogen-bonding interactions which are not accounted for in the calculations. The empirical structural-spectral relationship identified can potentially be applied to large, related amino acids and polypeptides in water.

  18. Identifying dominant conformations of N-acetyl-L-cysteine methyl ester and N-acetyl-L-cysteine in water: VCD signatures of the amide I and the C=O stretching bands.

    PubMed

    Poopari, Mohammad Reza; Dezhahang, Zahra; Xu, Yunjie

    2015-02-05

    Infrared (IR) and vibrational circular dichroism (VCD) spectra of N-Acetyl-L-Cysteine Methyl Ester (NALCME) and N-Acetyl-L-Cysteine (NALC) in D2O under different pHs were measured. We focus on the VCD signatures of the amide I and the C=O stretching spectral signatures of the neutral NALCME and NALC species and the related ones of the deprotonated NALC species in the region of 1800-1500 cm(-1). A sign inversion is observed for the amide I VCD band going from the neutral NALCME and NALC to the deprotonated NALC species. Density functional theory (DFT) calculations were carried out to search for the possible conformations of these three species and to simulate their IR and VCD spectra at the B3LYP/aug-cc-pVTZ level in the gas phase and with the polarization continuum model of water solvent. The most stable conformations found for neutral NALCME and NALC exhibit drastically difference VCD patterns, whereas those of deprotonated NALC show similar patterns. We establish an empirical structural-spectral relationship where the aforementioned VCD signatures can be used as spectral markers to identify dominant conformations of these two amino acid derivatives under different pHs. It is recognized that the dominant conformers identified using the VCD spectral markers differ from those based on the relative DFT energies for neutral NALCME and NALC. The influence of solvent on both the conformational geometries and their relative stabilities is discussed. The aforementioned discrepancy can be attributed to the explicit solute-solvent hydrogen-bonding interactions which are not accounted for in the calculations. The empirical structural-spectral relationship identified can potentially be applied to large, related amino acids and polypeptides in water.

  19. Structures of the N-acetyltransferase domain of Xylella fastidiosa N-acetyl-L-glutamate synthase/kinase with and without a His tag bound to N-acetyl-L-glutamate.

    PubMed

    Zhao, Gengxiang; Jin, Zhongmin; Allewell, Norma M; Tuchman, Mendel; Shi, Dashuang

    2015-01-01

    Structures of the catalytic N-acetyltransferase (NAT) domain of the bifunctional N-acetyl-L-glutamate synthase/kinase (NAGS/K) from Xylella fastidiosa bound to N-acetyl-L-glutamate (NAG) with and without an N-terminal His tag have been solved and refined at 1.7 and 1.4 Å resolution, respectively. The NAT domain with an N-terminal His tag crystallized in space group P4(1)2(1)2, with unit-cell parameters a=b=51.72, c=242.31 Å. Two subunits form a molecular dimer in the asymmetric unit, which contains ∼41% solvent. The NAT domain without an N-terminal His tag crystallized in space group P21, with unit-cell parameters a=63.48, b=122.34, c=75.88 Å, β=107.6°. Eight subunits, which form four molecular dimers, were identified in the asymmetric unit, which contains ∼38% solvent. The structures with and without the N-terminal His tag provide an opportunity to evaluate how the His tag affects structure and function. Furthermore, multiple subunits in different packing environments allow an assessment of the plasticity of the NAG binding site, which might be relevant to substrate binding and product release. The dimeric structure of the X. fastidiosa N-acetytransferase (xfNAT) domain is very similar to that of human N-acetyltransferase (hNAT), reinforcing the notion that mammalian NAGS is evolutionally derived from bifunctional bacterial NAGS/K.

  20. Amodiaquine-induced toxicity in isolated rat hepatocytes and the cytoprotective effects of taurine and/or N-acetyl cysteine

    PubMed Central

    Heidari, R.; Babaei, H.; Eghbal, M.A.

    2014-01-01

    Amodiaquine is an antimalarial drug used in the prophylaxis and treatment of this disease. However, hepatotoxicity as a life-threatening adverse effect is associated with its clinical use. We evaluated amodiaquine-induced toxicity in isolated rat hepatocytes as an in vitro model for studying drug-induced hepatotoxicity. This study attempts to investigate the protective effects of taurine and N-acetyl cysteine against the cytotoxicity induced by amodiaquine. Hepatocytes were prepared by the method of collagenase enzyme perfusion via portal vein. This technique is based on liver perfusion with collagenase after removal of calcium ion (Ca2+) with a chelator (ethylene glycol tetraacetic acid (EGTA) 0.5 mM). Cells were treated with different concentrations of amodiaquine, taurine and N-acetyl cysteine. Cell death, protein carbonylation, reactive oxygen species formation, lipid peroxidation, and mitochondrial depolarization were assessed as toxicity markers. Amodiaquine cytotoxic mechanism involved protein carbonylation as well as reactive oxygen species formation and lipid peroxidation. In addition, mitochondria seem to be a target for amodiaquine to induce cellular damage. Administration of taurine (200 μM) and/or N-acetyl cysteine (200 μM) reduced oxidative stress, lipid peroxidation and protein carbonylation caused by amodiaquine. Furthermore, amodiaquine-induced mitochondrial injury was significantly mitigated by taurine and/or N-acetyl cysteine. In glutathione-depleted cells, only N-acetyl cysteine protected hepatocytes against amodiaquine, and taurine showed no protective properties in this situation. Taurine and N-acetyl cysteine protect hepatocytes against amodiaquine probably via their antioxidant properties and counteracting oxidative stress. PMID:25657778

  1. A randomised, double blind, placebo-controlled trial of a fixed dose of N-acetyl cysteine in children with autistic disorder.

    PubMed

    Dean, Olivia M; Gray, Kylie M; Villagonzalo, Kristi-Ann; Dodd, Seetal; Mohebbi, Mohammadreza; Vick, Tanya; Tonge, Bruce J; Berk, Michael

    2017-03-01

    Oxidative stress, inflammation and heavy metals have been implicated in the aetiology of autistic disorder. N-acetyl cysteine has been shown to modulate these pathways, providing a rationale to trial N-acetyl cysteine for autistic disorder. There are now two published pilot studies suggesting efficacy, particularly in symptoms of irritability. This study aimed to explore if N-acetyl cysteine is a useful treatment for autistic disorder. This was a placebo-controlled, randomised clinical trial of 500 mg/day oral N-acetyl cysteine over 6 months, in addition to treatment as usual, in children with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnosis of autistic disorder. The study was conducted in Victoria, Australia. The primary outcome measures were the Social Responsiveness Scale, Children's Communication Checklist-Second Edition and the Repetitive Behavior Scale-Revised. Additionally, demographic data, the parent-completed Vineland Adaptive Behavior Scales, Social Communication Questionnaire and clinician-administered Autism Diagnostic Observation Schedule were completed. A total of 102 children were randomised into the study, and 98 (79 male, 19 female; age range: 3.1-9.9 years) attended the baseline appointment with their parent/guardian, forming the Intention to Treat sample. There were no differences between N-acetyl cysteine and placebo-treated groups on any of the outcome measures for either primary or secondary endpoints. There was no significant difference in the number and severity of adverse events between groups. This study failed to demonstrate any benefit of adjunctive N-acetyl cysteine in treating autistic disorder. While this may reflect a true null result, methodological issues particularly the lower dose utilised in this study may be confounders.

  2. Effects of N-acetyl-aspartyl glutamic acid and sodium cromoglycate on leukotriene B4 secretion by human leukocytes.

    PubMed

    Goldschmidt, P L; Vulliez-Le Normand, B; Briquet, I; Dray, F

    1990-07-01

    Peripheral leukocytes from allergic subjects were treated for 30 min with sodium cromoglycate (SCG) or with N-acetyl-aspartyl glutamic acid (NAAGA) and challenged for leukotriene B4 (LTB4) production with calcium ionophore A 23187. NAAGA significantly inhibits LTB4 release at concentrations of 10(-2) M (-86%), 5 x 10(-3) M (-49%) and 10(-3) M (-34%), while SCG was not able to block LTB4 production within the range of 10(-2)-10(-4) M. In spite of the fact that SCG and NAAGA are chemically unrelated and that both show antiallergic properties, only NAAGA is able in this model to block production of LTB4, a chemical mediator strongly involved in inflammatory and hypersensitivity reactions.

  3. Effect of N-acetyl-cysteine on liposomal and muscle model oxidation induced by reactive oxygen, nitrogen, and sulfur.

    PubMed

    Brannan, Robert G

    2011-08-01

    N-acetyl-cysteine (NAC), a naturally occurring thiol, is found in some fruits and vegetables, sometimes in concentrations higher than glutathione. The objective of this research was to determine the antioxidative effect of NAC in liposomal and muscle models challenged by different oxidizing systems, three that produce reactive oxygen species, two that produce reactive nitrogen species, and two that produce reactive sulfur. The antioxidative effect of cysteine and NAC was compared in the liposomes and NAC and BHT were compared in the muscle homogenates. Lipid hydroperoxides (LOOH), TBARS, and sulfydryls (protein and non-protein) were analyzed. Results indicated that NAC is a more effective inhibitor of lipid oxidation in systems induced by free radicals and reactive nitrogen than those that are induced by peroxides. NAC appears to be at least mildly antioxidative in both liposomal and muscle models, although it did not completely inhibit oxidation in liposomes and generally was not as effective as BHT in the muscle models.

  4. N-Acetyl-L-Cystein downregulates beta-amyloid precursor protein gene transcription in human neuroblastoma cells.

    PubMed

    Studer, R; Baysang, G; Brack, C

    2001-01-01

    The causes for the sporadic form of Alzheimer's disease (AD) are still poorly understood, except from the fact that age is an important risk factor. The main component of the characteristic amyloid plaques in brains of AD patients are Abeta peptides, derivatives of the amyloid precursor protein APP. Oxidative stress may contribute to the aetiology of AD by dysregulation of APP metabolism. Overexpression of the APP gene could result in an increased secretion of neurotoxic Abeta peptides, while preventing the overexpression might be protective. We here report that the antioxidant N-Acetyl-L-Cystein (NAC) downregulates APP gene transcription in human neuroblastoma cells. The effect is reversible when cells are returned to NAC free medium. These results open up new possibilities for the development of therapeutic agents that intervene at the transcriptional level.

  5. Urinary excretion of N-acetyl amino acids in patients with some inborn errors of amino acid metabolism.

    PubMed

    Jellum, E; Horn, L; Thoresen, O; Kvittingen, E A; Stokke, O

    1986-01-01

    Urinary organic acid profiles of patients with Maple Syrup Urine Disease (MSUD), hereditary tyrosinemia and phenylketonuria (PKU) have been studied by means of capillary GC-MS-computer technique. In addition to the characteristic metabolites of these disorders, increased amounts of N-acetylleucine, N-acetylisoleucine and N-acetylvaline were found in MSUD-urine. Increased excretion of N-acetylphenylalanine occurred in PKU, and in tyrosinemia both the latter compound and increased N-acetyltyrosine excretion were observed. These results together with literature reports of similar studies on patients with other aminoacidopathies may indicate that most disorders which result in accumulation of one or more specific amino acids, will convert a small fraction of them into their corresponding N-acetyl derivative.

  6. [Effect of carnosine and its N-acetyl derivative on the stability of erythrocytes in patients with alcoholism during abstinence].

    PubMed

    Prokop'eva, V D; Bohan, N A; Johnson, P; Boldyrev, A A

    1998-01-01

    The effects of carnosine, a natural dipeptide, and its derivative, N- acetyl-carnosine (Ac-carnosine), on the stability and shape of red blood cells obtained from abstinent alcoholics was studied. In the presence of both carnosine and Ac-carnosine, the erythrocytes of abstinent alcoholics show a statistically significant increase in their ability to resist acidic hemolysis. Investigations of microscope pictures also show that carnosine and Ac-carnosine have beneficial effects on the pathological state of abstinent alcoholic erythrocytes. The addition of carnosine and Ac-carnosine resulted in the normalization of cell morphology (in 12 and 17 out of 30 cases, respectively). These results may be due to the stabilizing and regenerating ability of these compounds on alcoholic erythrocytes.

  7. Chemo-attractant N-acetyl proline-glycine-proline induces CD11b/CD18-dependent neutrophil adhesion.

    PubMed

    Overbeek, Saskia A; Kleinjan, Marije; Henricks, Paul A J; Kamp, Vera M; Ricciardolo, Fabio L; Georgiou, Niki A; Garssen, Johan; Kraneveld, Aletta D; Folkerts, Gert

    2013-01-01

    Chronic inflammation in lung diseases contributes to lung tissue destruction leading to the formation of chemotactic collagen fragments such as N-acetylated proline-glycine-proline (N-ac-PGP). In the current study, we investigate whether N-ac-PGP influences β(2)-integrin activation and function in neutrophilic firm adhesion to endothelium. Human polymorphonuclear leukocytes (PMNs) were isolated from fresh human blood. Subsequently, a transmigration assay was performed to evaluate the active migration of PMNs towards N-ac-PGP. Furthermore, the effect of the tripeptide on β(2)-integrin activation was assessed by performing the adhesion assay using fibrinogen as a ligand. To determine whether this effect was due to conformational change of β(2)-integrins, antibodies against CD11b and CD18 were used in the adhesion assay and the expression pattern of CD11b was determined. Human neutrophils transmigrated through an endothelial cell layer in response to basolateral N-ac-PGP. N-ac-PGP induced also a neutrophil adherence to fibrinogen. Using functional blocking antibodies against CD11b and CD18, it was demonstrated that CD11b/CD18 (Mac-1) was responsible for the N-ac-PGP-induced firm adhesion of neutrophils to fibrinogen. Pertussis toxin decreased the Mac-1 activation indicating the involvement of G-proteins. N-ac-PGP most likely activated Mac-1 by initiating a conformational change, since the expression pattern of Mac-1 on the cell surface did not change significantly. Chemo-attractant N-acetyl proline-glycine-proline induces CD11b/CD18-dependent neutrophil adhesion. This is the first study to describe that the chemo-attractant N-ac-PGP also activates Mac-1 on the surface of neutrophils, which can additionally contribute to neutrophilic transmigration into the lung tissue during lung inflammation. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Protective effect of N-acetyl-L-cysteine against disulfiram-induced oxidative stress and apoptosis in V79 cells

    SciTech Connect

    Grosicka-Maciag, Emilia; Kurpios-Piec, Dagmara; Grzela, Tomasz; Czeczot, Hanna; Skrzycki, Michal; Szumilo, Maria; Rahden-Staron, Iwonna

    2010-11-01

    This work investigated the effect of N-acetyl-L-cysteine (NAC) on disulfiram (DSF) induced oxidative stress in Chinese hamster fibroblast cells (V79). An increase in oxidative stress induced by DSF was observed up to a 200 {mu}M concentration. It was evidenced by a statistically significant increase of both GSH{sub t} and GSSG levels, as well as elevated protein carbonyl (PC) content. There was no increase in lipid peroxidation (measured as TBARS). DSF increased CAT activity, but did not change SOD1 and SOD2 activities. Analysis of GSH related enzymes showed that DSF significantly increased GR activity, did not change Se-dependent GPx, but statistically significantly decreased non-Se-dependent GPx activity. DSF showed also pro-apoptotic activity. NAC alone did not produce any significant changes, besides an increase of GSH{sub t} level, in any of the variables measured. However, pre-treatment of cells with NAC ameliorated DSF-induced changes. NAC pre-treatment restored the viability of DSF-treated cells evaluated by Trypan blue exclusion assay and MTT test, GSSG level, and protein carbonyl content to the control values as well as it reduced pro-apoptotic activity of DSF. The increase of CAT and GR activity was not reversed. Activity of both GPx was significantly increased compared to their values after DSF treatment. In conclusion, oxidative properties are at least partially attributable to the cellular effects of disulfiram and mechanisms induced by NAC pre-treatment may lower or even abolish the observed effects. These observations illustrate the importance of the initial cellular redox state in terms of cell response to disulfiram exposure. -- Research Highlights: {yields}This report explores biological properties of disulfiram under a condition of modulated intra-cellular GSH level. It shows a protective role of N-acetyl-L-cysteine in V79 cells exposed to disulfiram (in GSH metabolism as well as in changes of antioxidant enzyme activity).

  9. Biosynthesis and turnover of O-acetyl and N-acetyl groups in the gangliosides of human melanoma cells

    SciTech Connect

    Manzi, A.E.; Sjoberg, E.R.; Diaz, S.; Varki, A.

    1990-08-05

    We and others previously described the melanoma-associated oncofetal glycosphingolipid antigen 9-O-acetyl-GD3, a disialoganglioside O-acetylated at the 9-position of the outer sialic acid residue. We have now developed methods to examine the biosynthesis and turnover of disialogangliosides in cultured melanoma cells and in Golgi-enriched vesicles from these cells. O-Acetylation was selectively expressed on di- and trisialogangliosides, but not on monosialogangliosides, nor on glycoprotein-bound sialic acids. Double-labeling of cells with (3H)acetate and (14C)glucosamine introduced easily detectable labels into each of the components of the ganglioside molecules. Pulse-chase studies of such doubly labeled molecules indicated that the O-acetyl groups turn over faster than the parent molecule. When Golgi-enriched vesicles from these cells were incubated with (acetyl-3H)acetyl-coenzyme A, the major labeled products were disialogangliosides. (Acetyl-3H)O-acetyl groups were found at both the 7- and the 9-positions, indicating that both 7-O-acetyl GD3 and 9-O-acetyl GD3 were synthesized by the action of O-acetyltransferase(s) on endogenous GD3. Analysis of the metabolically labeled molecules confirmed the existence of both 7- and 9-O-acetylated GD3 in the intact cells. Surprisingly, the major 3H-labeled product of the in vitro labeling reaction was not O-acetyl-GD3, but GD3, with the label exclusively in the sialic acid residues. Fragmentation of the labeled sialic acids by enzymatic and chemical methods showed that the 3H-label was exclusively in (3H)N-acetyl groups. Analyses of the double-labeled sialic acids from intact cells also showed that the 3H-label from (3H)acetate was exclusively in the form of (3H)N-acetyl groups, whereas the 14C-label was at the 4-position.

  10. Formation of the thioester, N-acetyl, S-lactoylcysteine, by reaction of N-acetylcysteine with pyruvaldehyde in aqueous solution. [in prebiotic evolution

    NASA Technical Reports Server (NTRS)

    Weber, A. L.

    1982-01-01

    N-acetylcysteine reacts efficiently with pyruvaldehyde (methylglyoxal) in aqueous solution (pH 7.0) in the presence of a weak base, like imidazole or phosphate, to give the thioester, N-acetyl, S-lactoylcysteine. Reactions of 100 mM N-acetylcysteine with 14 mM, 24 mM and 41 mM pyruvaldehyde yield, respectively, 86%, 76% and 59% N-acetyl, S-lactoylcysteine based on pyruvaldehyde. The decrease in the percent yield at higher pyruvaldehyde concentrations suggests that during its formation the thioester is not only consumed by hydrolysis, but also by reaction with some substance in the pyruvaldehyde preparation. Indeed, purified N-acetyl, S-lactoylcysteine disappears much more rapidly in the presence of pyruvaldehyde than in its absence. Presumably, N-acetyl, S-lactoylcysteine synthesis occurs by rearrangement of the hemithioacetal of N-acetylcysteine and pyruvaldehyde. The significance of this pathway of thioester formation to molecular evolution is discussed.

  11. Effects of the sulphydryl donor N-acetyl-L-cysteine on nerve conduction, perfusion, maturation and regeneration following freeze damage in diabetic rats.

    PubMed

    Love, A; Cotter, M A; Cameron, N E

    1996-08-01

    Peripheral nerve conduction velocity deficits in diabetic rats depend on decreased nerve perfusion, which may be related to increased free radical activity and impaired endogenous protection by the glutathione redox cycle. We studied the effect of treatment with the glutathione precursor N-acetyl-L-cysteine on nerve conduction, blood flow, maturation and regeneration. Two months of diabetes in mature rats caused 20% and 48% deficits in sciatic motor conduction velocity and endoneurial blood flow, respectively, which were largely corrected by N-acetyl-L-cysteine treatment during the second month. In young nondiabetic rats, sciatic motor conduction velocity increased by 31% over 6 weeks. Diabetes halved the conduction velocity maturation rate, however N-acetyl-L-cysteine treatment allowed a normal pattern of development. After 1 month of treated or untreated diabetes, the sciatic nerve was lesioned by a liquid nitrogen-cooled probe. Myelinated fibre regeneration distance, determined electrophysiologically, was reduced by 12.2% with diabetes; this was prevented by N-acetyl-L-cysteine treatment. Thus, the data stress the importance of free radical-mediated changes in the aetiology of experimental diabetic neuropathy.

  12. N-Acetyl-Cysteine as Effective and Safe Chelating Agent in Metal-on-Metal Hip-Implanted Patients: Two Cases

    PubMed Central

    Lonati, Davide; Ragghianti, Benedetta; Ronchi, Anna; Vecchio, Sarah; Locatelli, Carlo Alessandro

    2016-01-01

    Systemic toxicity associated with cobalt (Co) and chromium (Cr) containing metal hip alloy may result in neuropathy, cardiomyopathy, and hypothyroidism. However clinical management concerning chelating therapy is still debated in literature. Here are described two metal-on-metal hip-implanted patients in which N-acetyl-cysteine decreased elevated blood metal levels. A 67-year-old male who underwent Co/Cr hip implant in September 2009 referred to our Poison Control Centre for persisting elevated Co/Cr blood levels (from March 2012 to November 2014). After receiving oral high-dose N-acetyl-cysteine, Co/Cr blood concentrations dropped by 86% and 87% of the prechelation levels, respectively, and persisted at these latter concentrations during the following 6 months of follow-up. An 81-year-old female who underwent Co/Cr hip implant in January 2007 referred to our Centre for detection of high Co and Cr blood levels in June 2012. No hip revision was indicated. After a therapy with oral high-dose N-acetyl-cysteine Co/Cr blood concentrations decreased of 45% and 24% of the prechelation levels. Chelating agents reported in hip-implanted patients (EDTA, DMPS, and BAL) are described in few cases. N-acetyl-cysteine may provide chelating sites for metals and in our cases reduced Co and Cr blood levels and resulted well tolerable. PMID:27148463

  13. Formation of the thioester, N-acetyl, S-lactoylcysteine, by reaction of N-acetylcysteine with pyruvaldehyde in aqueous solution. [in prebiotic evolution

    NASA Technical Reports Server (NTRS)

    Weber, A. L.

    1982-01-01

    N-acetylcysteine reacts efficiently with pyruvaldehyde (methylglyoxal) in aqueous solution (pH 7.0) in the presence of a weak base, like imidazole or phosphate, to give the thioester, N-acetyl, S-lactoylcysteine. Reactions of 100 mM N-acetylcysteine with 14 mM, 24 mM and 41 mM pyruvaldehyde yield, respectively, 86%, 76% and 59% N-acetyl, S-lactoylcysteine based on pyruvaldehyde. The decrease in the percent yield at higher pyruvaldehyde concentrations suggests that during its formation the thioester is not only consumed by hydrolysis, but also by reaction with some substance in the pyruvaldehyde preparation. Indeed, purified N-acetyl, S-lactoylcysteine disappears much more rapidly in the presence of pyruvaldehyde than in its absence. Presumably, N-acetyl, S-lactoylcysteine synthesis occurs by rearrangement of the hemithioacetal of N-acetylcysteine and pyruvaldehyde. The significance of this pathway of thioester formation to molecular evolution is discussed.

  14. Fluorescent sensor for selective determination of copper ion based on N-acetyl-L-cysteine capped CdHgSe quantum dots.

    PubMed

    Wang, Qingqing; Yu, Xiangyang; Zhan, Guoqing; Li, Chunya

    2014-04-15

    Using N-acetyl-L-cysteine as a stabilizer, well water-dispersed, high-quality and stable CdHgSe quantum dots were facilely synthesized via a simple aqueous phase method. The as-prepared N-acetyl-L-cysteine capped CdHgSe quantum dots were thoroughly characterized by transmission electron microscopy, X-ray diffraction spectroscopy and FTIR. A fluorescent sensor for selective determination of copper ions was developed using N-acetyl-L-cysteine capped CdHgSe quantum dots as fluorescent probe. The fluorescence intensity of N-acetyl-L-cysteine capped CdHgSe quantum dots decreased when interacted with copper ions due to the formation of coordination complex and aggregates. The method possesses high selectivity and is not influenced by some potential interferences such as Ag(+), Zn(2+), Co(2+) and Ni(2+). Under the optimal conditions, the change of fluorescence intensity (ΔI) was linearly proportional to the concentration of copper ions in the range of 1.0×10(-9)-4.0×10(-7) mol L(-1), with a detection limit as low as 2.0×10(-10) mol L(-1) (S/N=3). The developed method had been successfully employed to determine Cu(2+) in shrimp and South-lake water samples, and the results were verified by atomic absorption spectroscopy. The fluorescent sensor was demonstrated to be selective, sensitive and simple for copper ion determination, and promise for practical applications.

  15. sup. alpha. N-acetyl derivatives of. beta. -endorphin-(1-31) and -(1-27) regulate the supraspinal antinociceptive activity of different opioids in mice

    SciTech Connect

    Garzon, J.; Sanchez-Blazquez, P. )

    1991-01-01

    {sup {alpha}}N-acetyl human {beta}-endorphin(1-31) injected icv to mice antagonized the analgesic activity of {beta}-endorphin-(1-31) and morphine whereas the analgesia evoked by DADLE and DAGO was enhanced by this treatment. The modulatory activity of {sup {alpha}}N-acetyl {beta}-endorphin-(1-31) was exhibited at remarkable low doses (fmols) reaching a maximum that persisted even though the dose was increased 100,000 times. The regulatory effect of a single dose of the acetylated neuropeptide lasted for 24h. The activity of {sup {alpha}}N-acetyl human {beta}-endorphin(1-31) was partially retained by the shorter peptide {sup {alpha}}N-acetyl human {beta}-endorphin-(1-27) and to a lesser extent by {beta}-endorphin-(1-27), {beta}-endorphin-(1-31) lacked this regulatory activity on opioid analgesia. Acetylated {beta}-endorphin-(1-31) displayed a biphasic curve when competing with 5 pM ({sup 125}I)-Tyr{sup 27} human {beta}-endorphin-(1-31) specific binding, the first step was abolished with an apparent IC{sub 50} of 0.35 nM, and the rest with an IC{sub 50} of 200 nM. It is suggested that {sup {alpha}}N-acetyl {beta}-endorphin-(1-31) changed the efficiency of the opioid analgesics by acting upon a specific substrate that is functionally coupled to the opioid receptor, presumably the guanine nucleotide binding regulatory proteins G{sub i}/G{sub 0}.

  16. Structural Investigation of a Novel N-Acetyl Glucosamine Binding Chi-Lectin Which Reveals Evolutionary Relationship with Class III Chitinases

    PubMed Central

    Patil, Dipak N.; Datta, Manali; Dev, Aditya; Dhindwal, Sonali; Singh, Nirpendra; Dasauni, Pushpanjali; Kundu, Suman; Sharma, Ashwani K.; Tomar, Shailly; Kumar, Pravindra

    2013-01-01

    The glycosyl hydrolase 18 (GH18) family consists of active chitinases as well as chitinase like lectins/proteins (CLPs). The CLPs share significant sequence and structural similarities with active chitinases, however, do not display chitinase activity. Some of these proteins are reported to have specific functions and carbohydrate binding property. In the present study, we report a novel chitinase like lectin (TCLL) from Tamarindus indica. The crystal structures of native TCLL and its complex with N-acetyl glucosamine were determined. Similar to the other CLPs of the GH18 members, TCLL lacks chitinase activity due to mutations of key active site residues. Comparison of TCLL with chitinases and other chitin binding CLPs shows that TCLL has substitution of some chitin binding site residues and more open binding cleft due to major differences in the loop region. Interestingly, the biochemical studies suggest that TCLL is an N-acetyl glucosamine specific chi-lectin, which is further confirmed by the complex structure of TCLL with N-acetyl glucosamine complex. TCLL has two distinct N-acetyl glucosamine binding sites S1 and S2 that contain similar polar residues, although interaction pattern with N-acetyl glucosamine varies extensively among them. Moreover, TCLL structure depicts that how plants utilize existing structural scaffolds ingenuously to attain new functions. To date, this is the first structural investigation of a chi-lectin from plants that explore novel carbohydrate binding sites other than chitin binding groove observed in GH18 family members. Consequently, TCLL structure confers evidence for evolutionary link of lectins with chitinases. PMID:23717482

  17. Enzymatic characterizations and activity regulations of N-acetyl-β-D-glucosaminidase from the spermary of Nile tilapia (Oreochromis niloticus).

    PubMed

    Zhang, Wei-Ni; Bai, Ding-Ping; Huang, Yi-Fan; Hu, Chong-Wei; Chen, Qing-Xi; Huang, Xiao-Hong

    2014-02-01

    N-Acetyl-β-D-glucosaminidase (NAGase) is proved to be correlated with reproduction of male animals. In this study, enzymatic characterizations of NAGase from spermary of Nile tilapia (Oreochromis niloticus) were investigated in order to further study its reproductive function in fish. Tilapia NAGase was purified to be PAGE homogeneous by the following techniques: (NH4)2SO4 fractionation (40-55%), DEAE-cellulose (DE-32) ion exchange chromatography, Sephadex G-200 gel filtration and DEAE-Sephadex (A-50). The specific activity of the purified enzyme was 4100 U/mg. The enzyme molecular weight was estimated as 118.0 kD. Kinetic studies showed that the hydrolysis of p-nitrophenyl-N-acetyl-β-D-glucosaminide (pNP-NAG) by the enzyme followed Michaelis-Menten kinetics. The Michaelis-Menten constant (Km) and maximum velocity (Vm) were determined to be 0.67 mM and 23.26 μM/min, respectively. The optimum pH and optimum temperature of the enzyme for hydrolysis of pNP-NAG was to be at pH 5.7 and 55°C, respectively. The enzyme was stable in a pH range from 3.3 to 8.1 at 37°C, and inactive at temperature above 45°C. The enzyme activity was regulated by the following ions in decreasing order: Hg(2+) > Zn(2+) > Cu(2+) > Pb(2+) > Mn(2+). The IC50 of Cu(2+), Zn(2+) and Hg(2+) was 1.23, 0.28, and 0.0027 mM, respectively. However, the ions Li(+), Na(+), K(+), Mg(2+) and Ca(2+) had almost no influence on enzyme activity. In conclusion, the enzymatic characterizations of NAGase from tilapia were special to the other animals, which were correlated with its living habit; besides, CuSO4 and ZnSO4 should used very carefully as insecticides in tilapia cultivation since they both had strong regulations on the enzyme.

  18. Spectrophotometric determination of N-acetyl-L-cysteine and N-(2-mercaptopropionyl)-glycine in pharmaceutical preparations.

    PubMed

    Kukoc-Modun, Lea; Radić, Njegomir

    2011-01-01

    A simple spectrophotometric method for the determination of N-acetyl-L-cysteine (NAC) and N-(2-mercaptopropionyl)glycine (MPG) in pharmaceutical preparations was developed, validated, and used. The proposed equilibrium method is based on a coupled two-step redox and complexation reaction. In the first step, Fe(III) is reduced to Fe(II) by NAC or MPG. Subsequently, Fe(II) is complexed with 2,4,6-tripyridyl-s-triazine (TPTZ). Several analytical parameters of the method were optimized for NAC and MPG analysis in the concentration range from 1.0 μM to 100.0 μM. Regression analysis of the calibration data showed a good correlation coefficient (0.9999). The detection limit of the method was 0.14 μM for NAC and 0.13 μM for MPG. The method was successfully applied to quantify NAC and MPG in pharmaceutical preparations. No interferences were observed from common pharmaceutical excipients.

  19. N-acetyl-cysteine attenuates remifentanil-induced postoperative hyperalgesia via inhibiting matrix metalloproteinase-9 in dorsal root ganglia

    PubMed Central

    Zhang, Wei; Sun, Yu-E; Ma, Zhengliang; Gu, Xiaoping

    2017-01-01

    Treatment of remifentanil-induced postoperative hyperalgesia (RIH) remains a clinical challenge because the mechanisms are not fully understood. Matrix metalloproteinase-9 (MMP-9) is a key component in neuroinflammation because of its facilitation of pro-inflammatory cytokine maturation. Therefore, inhibition of MMP-9 may represent a novel therapeutic approach to the treatment of RIH. Sprague-Dawley rats were randomly divided into three groups: Control, Incision and Remifentanil. A right plantar surgical incision was performed in Group Incision, and intraoperative remifentanil (0.04 mg/kg, 0.4 ml) was infused subcutaneously for 30 min in Group Remifentanil. The results indicated that intraoperative remifentanil induced an up-regulation and activation of MMP-9 in DRGs but not spinal cords. MMP-9 was expressed primarily in DRG neurons co-expressing mu opioid receptors (MOR), and elicited interleukin-1β (IL-1β) cleavage in DRG neurons and satellite glial cells (SGCs). Intraperitoneal injection of N-acetyl-cysteine (NAC), a broadly used safe drug, significantly attenuated RIH via suppressing the activation of MMP-9 in DRGs. NAC inhibited the cleavage of IL-1β in DRGs, which is a critical substrate of MMP-9, and markedly suppressed glial activation and neuron excitability in spinal dorsal horn induced by remifentanil. These results demonstrated that NAC can effectively alleviate RIH via powerfully inhibiting MMP-9 activation in DRGs. PMID:28199982

  20. Reperfusion liver injury-induced superoxide dismutase and catalase expressions and the protective effects of N-acetyl cysteine.

    PubMed

    Chen, C F; Hsueh, C W; Tang, T S; Wang, D; Shen, C Y; Pei, J S

    2007-05-01

    Reperfusion of the ischemic liver results in the generation of oxygen radicals. In this study, we analyzed if the mRNA and protein expressions of superoxide dismutase (SOD) and catalase increased after ischemia (I) and reperfusion (R) of the rat liver. Ischemia was induced by clamping off the common hepatic artery and portal vein of rats for 40 minutes, which were then reperfused for 90 minutes. Blood samples collected prior to I and after R were analyzed for hydroxyl radical (.OH), nitric oxide (NO), and alanine transferase (ALT). Liver tissues were used to analyze the SOD and catalase mRNA and protein expressions by real-time polymerase chain reaction and Western blot. The results showed that this protocol resulted in elevation of the blood ALT, NO, and .OH levels (P<.001). mRNA (P<.01) and protein expressions (P<.05) of SOD and catalase were all increased. Pretreatment with antioxidant, N-acetyl cysteine, attenuated the liver injury. These results indicate that reperfusion of the ischemic liver induced antioxidant enzymes expressions so that oxygen radicals are scavenged. Oxygen radical scavenger could further attenuate the I/R-induced liver injury.

  1. Attenuation of rotenone toxicity in SY5Y cells by taurine and N-acetyl cysteine alone or in combination.

    PubMed

    Alkholifi, Faisal K; Albers, David S

    2015-10-05

    There is accumulating evidence that supports the involvement of reactive oxygen species (ROS), mitochondrial dysfunction and inflammation in the pathogenesis of neurodegenerative diseases. Thus, it is plausible that a multi-targeted therapeutic approach may be a more effective strategy to retard or even potentially halt the progression of the disease. Taurine is an organic acid that has a role in the regulation of oxidative stress and promoting mitochondrial normal functions, and N-Acetyl cysteine (NAC) is a well-known anti-oxidant and glutathione precursor. The main purpose of this study was to examine the cytoprotective effects of taurine alone or in combination with NAC against rotenone-induced toxicity in the SH-SY5Y neuroblastoma cell line. Taurine treatment produced a concentration-dependent reduction in rotenone-induced cell death. From this, we tested sub-effective concentrations of taurine in combination with low, sub-effective concentrations of NAC against rotenone toxicity, and found the combined treatment afforded greater cytoprotection than either treatment alone. The combined taurine/NAC treatment also attenuated rotenone-induced reductions in aconitase activity suggesting the cytoprotection afforded by the combined treatment may be associated with anti-oxidative mechanisms. Together, our data suggest that a multi-targeted approach may yield new avenues of research exploring the utility of combining therapeutic agents with different mechanisms of actions at concentrations lower than previously tested and shown to be cytoprotective. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Isoforms of an N-acetyl-beta-D-glucosaminidase from the Antarctic krill, Euphausia superba: purification and antibody production.

    PubMed

    Peters, G; Saborowski, R; Mentlein, R; Buchholz, F

    1998-08-01

    Two forms of the chitinolytic enzyme N-acetyl-beta-D-glucosaminidase (NAGase, EC 3.2.1.52) have been isolated from the Antarctic krill, Euphausia superba, in order to study their potential role in temperature adaptation processes. A chromatographic protocol was developed that allowed complete separation of the two enzyme forms, named NAGase B and NAGase C. The latter was purified to homogeneity with 600-fold enrichment and a yield of 17%. The molecular mass was 150 kDa. NAGase B showed characteristics of a glycoprotein due to affinity towards concanavalin A sepharose, while NAGase C did not. Highly specific polyclonal antibodies to NAGase C [anti-(E. superba-NAGase C)-IgG] showed only negligible cross-reactivity with NAGase B isoforms. A comparison with the Northern krill, Meganyctiphanes norvegica, revealed a corresponding chromatographic pattern with two main activity peaks, for differentiation named NAGase II and NAGase III. Application of the antibody on M. norvegica revealed a high specificity toward NAGase III and a low cross-reactivity with NAGase II. First indication is given that the two forms are no isoenzymes in a strict sense but instead may have different functions in the metabolism of krill.

  3. N-acetyl-heparin attenuates acute lung injury caused by acid aspiration mainly by antagonizing histones in mice.

    PubMed

    Zhang, Yanlin; Zhao, Zanmei; Guan, Li; Mao, Lijun; Li, Shuqiang; Guan, Xiaoxu; Chen, Ming; Guo, Lixia; Ding, Lihua; Cong, Cuicui; Wen, Tao; Zhao, Jinyuan

    2014-01-01

    Acute lung injury (ALI) is the leading cause of death in intensive care units. Extracellular histones have recently been recognized to be pivotal inflammatory mediators. Heparin and its derivatives can bind histones through electrostatic interaction. The purpose of this study was to investigate 1) the role of extracellular histones in the pathogenesis of ALI caused by acid aspiration and 2) whether N-acetyl-heparin (NAH) provides more protection than heparin against histones at the high dose. ALI was induced in mice via intratracheal instillation of hydrochloric acid (HCl). Lethality rate, blood gas, myeloperoxidase (MPO) activity, lung edema and pathological changes were used to evaluate the degree of ALI. Heparin/NAH was administered intraperitoneally, twice a day, for 3 days or until death. Acid aspiration caused an obvious increase in extracellular histones. A significant correlation existed between the concentration of HCl aspirated and the circulating histones. Heparin/NAH (10 mg/kg) improved the lethality rate, blood gas, MPO activity, lung edema and pathological score. At a dose of 20 mg/kg, NAH still provided protection, however heparin tended to aggravate the injury due to hemorrhagic complications. The specific interaction between heparin and histones was verified by the binding assay. In summary, high levels of extracellular histones can be pathogenic in ALI caused by acid aspiration. By neutralizing extracellular histones, heparin/NAH can offer similar protection at the moderate doses. At the high dose, NAH provides better protection than heparin.

  4. N-Acetyl cysteine (NAC) inhibits proliferation, collagen gene transcription, and redox stress in rat palatal mucosal cells.

    PubMed

    Sato, N; Ueno, T; Kubo, K; Suzuki, T; Tsukimura, N; Att, W; Yamada, M; Hori, N; Maeda, H; Ogawa, T

    2009-12-01

    Control of hyperplastic and invasively growing gingival tissue is crucial for maintaining normal oral function and for successful bone regenerative therapy. We tested the hypothesis that materials containing N-acetyl cysteine (NAC), an antioxidant cysteine derivative, can control proliferation and function of oral mucosal cells. Oral mucosal cells derived from the rat palatal tissue were cultured with or without NAC at different concentrations (2.5-10.0mM). To simulate inflammatory conditions, cultures were treated with hydrogen peroxide. NAC was also applied via collagen materials in membrane and sponge forms to explore the clinical applicability. The redox balance inside the cells was evaluated by measuring the concentration of intracellular glutathione (GSH). Adding NAC into cultures of oral mucosal cells reduced their proliferation, transcriptional expression, and collagen production in an NAC-concentration-dependent manner without cytotoxic effects. Furthermore, NAC substantially reduced the hydrogen peroxide-induced elevation of cellular proliferation and collagen production. The controlling effects of NAC were also demonstrated in cells cultured on NAC-containing collagen materials and were associated with an increase in intracellular glutathione (GSH) reserves and a decrease in the oxidized form of glutathione (GSSG). These results indicate that NAC may abrogate inflammation- or oxidative-stress-induced hyperfunction of oral mucosal cells and that it can be delivered effectively via biodegradable materials. This study provides a basis to explore NAC-containing biomaterials that are functionalized to control oral soft tissue growth and function without cytotoxicity.

  5. Highly selective colorimetric assay for nickel ion using N-acetyl- l-cysteine-functionalized silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Shang, Yan; Wu, Fangying; Qi, Li

    2012-10-01

    A colorimetric assay based on silver nanoparticles (NAC-Ag NPs) capped with N-acetyl- l-cysteine (C5H9NO3S, NAC) has been developed which exhibits highly selectivity towards Ni2+ over other cations such as Al3+, Cr3+, Fe3+, Co2+, Pb2+, Ba2+, Cd2+, Fe2+, Cu2+, Hg2+, Zn2+, Mn2+, Ag+, Mg2+, Ca2+, Na+, and K+ under specified conditions. Silver nanoparticles were prepared by reducing AgNO3 with sodium borohydride (NaBH4) in the presence of NAC. The infrared spectra suggested that NAC was successfully capped on the surface of the silver nanoparticles. In the presence of Ni2+, rapid aggregation of NAC-Ag NPs was induced along with color change from yellow to deep orange. The absorbance ratio ( A 550/ A 390) was linear with the concentration of Ni2+ in the wide range from 2 to 48 μM with a detection limit of 0.23 μM. The proposed method was applied successfully to the determination of Ni2+ in tap water samples, and the recoveries were from 92 to 106 %.

  6. Aqueous based synthesis of N-acetyl-L-cysteine capped ZnSe nanocrystals with intense blue emission

    NASA Astrophysics Data System (ADS)

    Soheyli, Ehsan; Sahraei, Reza; Nabiyouni, Gholamreza

    2016-10-01

    In this work a very simple reflux route for preparation of ZnSe nanocrystals with minor modification and faster preparation over conventional ones is introduced. X-ray diffraction analysis indicated that the ZnSe nanocrystals have a cubic structure. The complete disappearance of the S-H band in FT-IR spectrum of N-acetyl-L-cysteine capped ZnSe nanocrystals was an indication over formation of Zn-thiol covalent bonds at the surface of the nanocrystals which results in passivation of small nanocrystals. The strong size-quantization regime was responsible of significant blue shift in absorption/emission spectra. Using the well-known calculations, band gap and Urbach energy of the ZnSe nanocrystals were measured and their average size was estimated optically to be around 4.6 nm along with the TEM image. A dark blue emission with higher relative intensity of excitonic to trap emissions (compared to conventional method), very narrow excitonic emission peak of about 16 nm and remarkable stability was obtained from the ZnSe nanocrystals.

  7. Community shifts of actively growing lake bacteria after N-acetyl-glucosamine addition: improving the BrdU-FACS method.

    PubMed

    Tada, Yuya; Grossart, Hans-Peter

    2014-02-01

    In aquatic environments, community dynamics of bacteria, especially actively growing bacteria (AGB), are tightly linked with dissolved organic matter (DOM) quantity and quality. We analyzed the community dynamics of DNA-synthesizing and accordingly AGB by linking an improved bromodeoxyuridine immunocytochemistry approach with fluorescence-activated cell sorting (BrdU-FACS). FACS-sorted cells of even oligotrophic ecosystems in winter were characterized by 16S rRNA gene analysis. In incubation experiments, we examined community shifts of AGB in response to the addition of N-acetyl-glucosamine (NAG), one of the most abundant aminosugars in aquatic systems. Our improved BrdU-FACS analysis revealed that AGB winter communities of oligotrophic Lake Stechlin (northeastern Germany) substantially differ from those of total bacteria and consist of Alpha-, Beta-, Gamma-, Deltaproteobacteria, Actinobacteria, Candidatus OP10 and Chloroflexi. AGB populations with different BrdU-fluorescence intensities and cell sizes represented different phylotypes suggesting that single-cell growth potential varies at the taxon level. NAG incubation experiments demonstrated that a variety of widespread taxa related to Alpha-, Beta-, Gammaproteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Planctomycetes, Spirochaetes, Verrucomicrobia and Chloroflexi actively grow in the presence of NAG. The BrdU-FACS approach enables detailed phylogenetic studies of AGB and, thus, to identify those phylotypes which are potential key players in aquatic DOM cycling.

  8. Vibrational Spectroscopy and Gas-Phase Thermochemistry of the Model Dipeptide N-Acetyl Glycine Methyl Amide

    NASA Astrophysics Data System (ADS)

    Leavitt, Christopher; Raston, Paul; Moody, Grant; Shirley, Caitlyne; Douberly, Gary

    2014-06-01

    The structure-function relationship in proteins is widely recognized, motivating numerous investigations of isolated neutral and ionic polypeptides that generally employ conformation specific, multidimensional UV and IR spectroscopies. This data taken in conjunction with computed harmonic frequencies has provided a snapshot of the underlying molecular physics at play in many polypeptides, but few experiments have been able to probe the energetics of these systems. In this study, we use vibrational spectroscopy to measure the gas-phase enthalpy change for isomerization between two conformations of the dipeptide N-acetyl glycine methyl amide (NAGMA). A two-stage oven source is implemented producing a gas-phase equilibrium distribution of NAGMA molecules that is flash frozen upon pickup by He nanodroplets. Using polarization spectroscopy, the IR spectrum is assigned to a mixture of two conformers having intramolecular hydrogen bonds made up of either five- or seven-membered rings, C5 and C7, respectively. The interconversion enthalpy, obtained from the van't Hoff relation, is 4.52{±}0.12 kJ/mol for isomerization from the C7 to the C5-conformer. This experimental measurement is compared to computations employing a broad range of theoretical methods.

  9. [Isoforms A and B of lysosomal N-acetyl-beta-D-hexosaminidase in serum and urine of parenterally fed patients].

    PubMed

    Raczkowska, Katarzyna; Zalewska-Szajda, Beata; Chojnowska, Sylwia; Kepka, Alina; Raczkowski, Krzysztof; Waszkiewicz, Napoleon; Siedlecka-Czykier, Edyta; Dadan, Jacek; Snarska, Jadwiga; Zwierz, Krzysztof; Ładny, Jerzy Robert; Szajda, Sławomir Dariusz

    2013-05-01

    Parenteral nutrition entails numerous metabolic complications resulting from food bypass of the gastrointestinal tract. Up to now have not been established all complications of parenteral nutrition, despite intensive research and clinical observations. Knowledge of the biochemical changes resulting from parenteral nutrition is essential to effective prevention, early detection and effective treatment of the metabolic disorders induced by parenteral nutrition. The aim of the study was to evaluate the catabolism of glycoconjugates of parenterally fed patients, reflected by the activity of N-acetyl-beta-D-hexosaminidase (HEX): HEX A and HEX B isoenzymes in serum and urine. Samples of blood and urine were collected from 23 patients: before intravenous alimentation, at start, as well as of fifth and tenth day of parenteral nutrition. The activity of HEX A and HEX B in serum and urine was determined by the colorimetric method of Zwierz et al. as modified by Marciniak et al. The activity of urinary HEXA and HEX B has been calculated per 1 mg of creatinine. The activity of serum HEXA significantly decreased at fifth day, in comparison to the activity before parenteral alimentation, and significantly increased at tenth day of parenteral nutrition. The activity of HEX B in serum increased significantly at fifth and tenth day of the parenteral nutrition. Parenteral nutrition alter the catabolism of glycoconjugates, reflected by significant changes in serum HEX A and HEX B activities. Urine was the not appropriate material to evaluate the catabolism of glycoconjugates in view of HEX A and HEX B activities.

  10. Chronic treatment with N-acetyl-cystein delays cellular senescence in endothelial cells isolated from a subgroup of atherosclerotic patients

    PubMed Central

    Voghel, Guillaume; Thorin-Trescases, Nathalie; Farhat, Nada; Mamarbachi, Aida M.; Villeneuve, Louis; Fortier, Annik; Perrault, Louis P.; Carrier, Michel; Thorin, Eric

    2013-01-01

    Endothelial senescence may contribute to the pathogenesis of age-related vascular disorders. Furthermore, chronic exposure to risk factors for cardiovascular disease (CVD) accelerates the effects of chronological aging by generating stress-dependent damages, including oxidative stress, therefore promoting stress-induced premature senescence. Our objective was to determine whether a chronic treatment with an antioxidant (N-acetyl-cystein, NAC) could delay senescence of endothelial cells (EC) isolated and cultured from arterial segments of patients with severe coronary artery disease. If EC were considered as one population (n = 26), chronic NAC treatment slightly shortened telomere attrition rate associated with senescence but did not significantly delay the onset of endothelial senescence. However, in a subgroup of NAC-treated EC (n = 15) cellular senescence was significantly delayed, NAC decreased lipid peroxidation (HNE), activated the catalytic subunit of telomerase (hTERT) and inhibited telomere attrition. In contrast, in another subgroup of EC (n = 11) characterized by initial short telomeres, no effect of NAC on HNE and high levels of DNA damages, the antioxidant was not beneficial on senescence, suggesting an irreversible stress-dependent damage. In conclusion, chronic exposure to NAC can delay senescence of diseased EC via hTERT activation and transient telomere stabilization, unless oxidative stress-associated cell damage has become irreversible. PMID:18302967

  11. N-Acetyl-Heparin Attenuates Acute Lung Injury Caused by Acid Aspiration Mainly by Antagonizing Histones in Mice

    PubMed Central

    Zhang, Yanlin; Zhao, Zanmei; Guan, Li; Mao, Lijun; Li, Shuqiang; Guan, Xiaoxu; Chen, Ming; Guo, Lixia; Ding, Lihua; Cong, Cuicui; Wen, Tao; Zhao, Jinyuan

    2014-01-01

    Acute lung injury (ALI) is the leading cause of death in intensive care units. Extracellular histones have recently been recognized to be pivotal inflammatory mediators. Heparin and its derivatives can bind histones through electrostatic interaction. The purpose of this study was to investigate 1) the role of extracellular histones in the pathogenesis of ALI caused by acid aspiration and 2) whether N-acetyl-heparin (NAH) provides more protection than heparin against histones at the high dose. ALI was induced in mice via intratracheal instillation of hydrochloric acid (HCl). Lethality rate, blood gas, myeloperoxidase (MPO) activity, lung edema and pathological changes were used to evaluate the degree of ALI. Heparin/NAH was administered intraperitoneally, twice a day, for 3 days or until death. Acid aspiration caused an obvious increase in extracellular histones. A significant correlation existed between the concentration of HCl aspirated and the circulating histones. Heparin/NAH (10 mg/kg) improved the lethality rate, blood gas, MPO activity, lung edema and pathological score. At a dose of 20 mg/kg, NAH still provided protection, however heparin tended to aggravate the injury due to hemorrhagic complications. The specific interaction between heparin and histones was verified by the binding assay. In summary, high levels of extracellular histones can be pathogenic in ALI caused by acid aspiration. By neutralizing extracellular histones, heparin/NAH can offer similar protection at the moderate doses. At the high dose, NAH provides better protection than heparin. PMID:24816808

  12. Influence of the substituent on amide nitrogen atom of N-acetyl tyrosine on interactions with β-cyclodextrin

    NASA Astrophysics Data System (ADS)

    Mrozek, Justyna; Banecki, Bogdan; Sikorska, Emilia; Skwierawska, Agnieszka; Karolczak, Jerzy; Wiczk, Wiesław

    2008-12-01

    The influence of substituent on amide nitrogen atom on the interactions of N-acetyl tyrosine amides with β-cyclodextrin was studied by means of steady-state and time-resolved fluorescence spectroscopy, 2D 1H NMR, and microcalorimetry. In comparison with AcTyr-OH a primary amide group only in a small degree modified the binding constant with β-CD, regardless of the structure (linear or branched) and the length of n-alkyl substituent which for primary amides (methyl, ethyl, n-propyl, iso-propyl, n-butyl, and sec-butyl), as determined from the microcalorimetric titrations, is in the range from 122 M -1 to 190 M -1, except for t-butyl substituent for which the highest binding constant (over 500 M -1) was determined. Moreover, for a branched substituent binding constants are a little higher in comparison with n-alkyl ones. For secondary amides (di-methyl, di-ethyl, di- n-propyl, di- iso-propyl, and di- iso-butyl) the binding constants are higher (in the range from 270 M -1 to 410 M -1).

  13. Stimulatory effect of N-acetyl Muramyl dipeptide in vivo: proliferation of bone marrow progenitor cells in mice.

    PubMed Central

    Wuest, B; Wachsmuth, E D

    1982-01-01

    The effects of single and multiple injections of N-acetyl muramyl dipeptide (MDP) on peripheral leukocytes, colony-forming cells (i.e., bone marrow granulocyte-macrophage progenitor cells), and the humoral immune response (to bovine serum albumin) were investigated in mice. Whereas low doses of MDP (0.1 to 1 mg/kg) provoked lymphocytosis, larger doses (10 mg/kg upward) resulted in lymphocytopenia and an increase in the number of young stab neutrophils and monocytes. MDP induced a dose-dependent increase in the number of bone-marrow macrophage progenitor cells, the maximum being reached by a dose around 10 mg/kg. A 50% increase in the maximum effect was produced by a dose around 0.1 mg/kg. The higher the dose, the longer the increase in these progenitor cells persisted. MDP mediated a dose-dependent antibody response to small amounts of bovine serum albumin, correlating with the proliferation of progenitor cells. PMID:7118246

  14. Effect of N-acetyl-l-cysteine on insulin resistance caused by prolonged free fatty acid elevation.

    PubMed

    Pereira, Sandra; Shah, Anu; George Fantus, I; Joseph, Jamie W; Giacca, Adria

    2015-04-01

    Circulating free fatty acids (FFAs) are elevated in obesity and cause insulin resistance. The objective of the current study was to determine whether the antioxidant N-acetyl-l-cysteine (NAC) prevented hepatic and peripheral insulin resistance caused by prolonged elevation of plasma FFAs. Chronically cannulated Wistar rats received saline (SAL), Intralipid plus heparin (IH), IH plus NAC, or NAC i.v. infusion for 48 h. Insulin sensitivity was determined using the hyperinsulinemic-euglycemic clamp with tritiated glucose tracer. IH induced hepatic and peripheral insulin resistance (P<0.05). NAC co-infusion did not prevent insulin resistance in the liver, although it was able to prevent peripheral insulin resistance. Prolonged IH infusion did not appear to induce oxidative stress in the liver because hepatic content of protein carbonyl, malondialdehyde, and reduced to oxidized glutathione ratio did not differ across treatment groups. In alignment with our insulin sensitivity results, IH augmented skeletal muscle protein carbonyl content and this was prevented by NAC co-infusion. Taken together, our results indicate that oxidative stress mediates peripheral, but not hepatic, insulin resistance resulting from prolonged plasma FFA elevation. Thus, in states of chronic plasma FFA elevation, such as obesity, antioxidants may protect against peripheral but not hepatic insulin resistance.

  15. N-acetyl-cysteine protects against DNA damage associated with lead toxicity in HepG2 cells.

    PubMed

    Yedjou, Clement G; Tchounwou, Christine K; Haile, Samuel; Edwards, Falicia; Tchounwou, Paul B

    2010-01-01

    Lead toxicity has been associated with its ability to interact and damage DNA. However, its molecular mechanisms of action are not fully understood. In vitro studies in our laboratory indicated that lead nitrate (PbNO3) induces cytotoxicity and oxidative stress to human liver carcinoma (HepG2) cells in a dose-dependent manner. In this research, we hypothesized that n-acetyl-cysteine (NAC), a known antioxidant compound, affords protection against lead-induced cell death associated with genotoxic damage. To test this hypothesis, HepG2 cells were treated either with a physiologic dose of NAC, NAC plus PbNO3, or PbNO3 alone, followed by incubation in humidified 5% CO2 incubator at 37 degrees C for 48 hr. The cell viability was determined by trypan blue exclusion test. The degree of DNA damage was detected by micro gel electrophoresis (comet) assay. Our results showed that lead exposure induces a substantial cytotoxicity as well as a significant genotoxicity to HepG2 cells. However, co-treatment with a physiologic dose (500 microM) of NAC slightly increases cell viability, and significantly reduced (P < .05) the degree of DNA damage. Hence, NAC treatment may be a promising therapeutic candidate for chemoprevention against lead toxicity, based on its ability to scavenge free radicals.

  16. Inhibition of sulfur mustard-increased protease activity by niacinamide, N-acetyl-L-cysteine or dexamethasone

    SciTech Connect

    Cowan, F.M.; Broomfield, C.A.; Smith, W.J.

    1991-03-11

    The pathologic mechanism of sulfur mustard-induced skin vesication is as yet undefined. Papirmeister et al. have postulated a biochemical mechanism for sulfur mustard-induced cutaneous injury involving sequelae of DNA alkylation, metabolic disruption resulting in NAD+ depletion and activation of protease. The authors have utilized a chromogenic peptide substrate assay to establish that human peripheral blood lymphocytes exposed 24 hr previously to sulfur mustard exhibited an increase in proteolytic activity. Doses of compounds known to alter the biochemical events associated with sulfur mustard exposure or reduce protease activity were tested in this system for their ability to block the sulfur mustard-induced protease activity. Treatment with niacinamide 1 hr after or with N-acetyl-L-cysteine or dexamethasone 24 hr prior to sulfur mustard exposure resulted in a decrease of 39%, 33% and 42% respectively of sulfur mustard-increased protease activity. These data suggest that therapeutic intervention into the biochemical pathways that culminate in protease activation might serve as an approach to treatment of sulfur mustard-induced pathology.

  17. Prevention and Mitigation of Acute Death of Mice after Abdominal Irradiation by the Antioxidant N-Acetyl-cysteine (NAC)

    PubMed Central

    Jia, Dan; Koonce, Nathan A.; Griffin, Robert J.; Jackson, Cassie; Corry, Peter M.

    2010-01-01

    Gastrointestinal (GI) injury is a major cause of acute death after total-body exposure to large doses of ionizing radiation, but the cellular and molecular explanations for GI death remain dubious. To address this issue, we developed a murine abdominal irradiation model. Mice were irradiated with a single dose of X rays to the abdomen, treated with daily s.c. injection of N-acetyl-l-cysteine (NAC) or vehicle for 7 days starting either 4 h before or 2 h after irradiation, and monitored for up to 30 days. Separately, mice from each group were assayed 6 days after irradiation for bone marrow reactive oxygen species (ROS), ex vivo colony formation of bone marrow stromal cells, and histological changes in the duodenum. Irradiation of the abdomen caused dose-dependent weight loss and mortality. Radiation-induced acute death was preceded not only by a massive loss of duodenal villi but also, surprisingly, abscopal suppression of stromal cells and elevation of ROS in the nonirradiated bone marrow. NAC diminished these radiation-induced changes and improved 10- and 30-day survival rates to >50% compared with <5% in vehicle-treated controls. Our data establish a central role for abscopal stimulation of bone marrow ROS in acute death in mice after abdominal irradiation. PMID:20426657

  18. In vitro effects of N-acetyl cysteine alone and in combination with antibiotics on Prevotella intermedia.

    PubMed

    Moon, Ji-Hoi; Jang, Eun-Young; Shim, Kyu Sang; Lee, Jin-Yong

    2015-05-01

    N-acetyl cysteine (NAC) is an antioxidant that possesses anti-inflammatory activities in tissues. In the field of dentistry, NAC was demonstrated to prevent the expression of LPS-induced inflammatory mediators in phagocytic cells and gingival fibroblasts during the inflammatory process, but the effect of NAC on oral pathogens has been rarely studied. Here, we examined the effect of NAC against planktonic and biofilm cells of Prevotella intermedia, a major oral pathogen. NAC showed antibacterial activity against the planktonic P. intermedia with MIC value of 3 mg/ml and significantly decreased biofilm formation by the bacterium even at sub MIC. NAC did not affect the antibiotic susceptibility of planktonic P. intermedia, showing indifference (fractional inhibitory concentration index of 0.5-4) results against the bacterium in combination with ampicillin, ciprofloxacin, tetracycline or metronidazole. On the other hand, viability of the pre-established bacterial biofilm exposed to the antibiotics except metronidazole was increased in the presence of NAC. Collectively, NAC may be used for prevention of the biofilm formation by P. intermedia rather than eradication of the pre-established bacterial biofilm. Further studies are required to explore antibacterial and anti-biofilm activity of NAC against mixed population of oral bacteria and its modulatory effect on antibiotics used for oral infectious diseases.

  19. The effect of N-acetyl-glucosamine on stratum corneum desquamation and water content in human skin.

    PubMed

    Mammone, T; Gan, D; Fthenakis, C; Marenus, K

    2009-01-01

    Alpha-hydroxy acids have been used topically to treat skin for both dermatological and cosmetic problems for many years. Though there are many known benefits of the use of alpha-hydroxy acids on skin, there have been recent reports that topical treatments with alpha-hydroxy acids increase skin damage resulting from UVB. Additionally, high concentrations of alpha-hydroxy acids by themselves have also been found to cause skin irritation. In order to find alternatives to alpha-hydroxy acids, we investigated a variety of amino sugar compounds that were previously reported to inhibit the reaggregation of dissociated corneocytes by modulating cellular adhesion. In vivo, we observed that topical treatments with a formulation containing N-acetyl-glucosamine (NAG) led to an increase in skin moisturization, a decrease in skin flakiness, and the normalization of stratum corneum exfoliation. In vitro, we observed an upregulation of differentiation markers, keratin 10 and involucrin, in keratinocytes treated with NAG. CD44 is a lectin cell adhesion molecule that is also expressed in keratinocytes. Amino sugars such as NAG may competitively bind to CD44, modulating keratinocyte cellular adhesion. We hypothesize that these amino sugars modulate keratinocyte cellular adhesion and differentiation, leading to the normalization of stratum corneum exfoliation. We propose the use of amino sugars such as NAG as alternative compounds to replace the use of alpha-hydroxy acids in skin care.

  20. Effects of N-acetyl-L-cysteine on fish hepatoma cells treated with mercury chloride and ionizing radiation.

    PubMed

    Kim, Jin Kyu; Han, Min; Nili, Mohammad

    2011-11-01

    Organisms are exposed to natural radiations from cosmic or terrestrial origins. Furthermore the combined action of radiation with various chemicals is an inevitable feature of modern life. Radiation is known to cause cell death, mainly due to its ability to produce reactive oxygen species in cells. N-acetyl-L-cysteine (NAC) is a well-known sulfhydryl-containing antioxidant whose role in radioprotection has been reported. Synergistic effects of radiation and mercury chloride on human cells was previously reported by the authors. Based on the previous report, this study was designed to assess the synergistic effects of radiation and mercury chloride on fish hepatoma cells, as well as to investigate the protective effects of NAC on the cells. The cytotoxicity of radiation was enhanced in the presence of mercury chloride. NAC in lower concentrations prevented cells from death after irradiation with lower doses (<300 Gy) while it did not prevent cells from radiation-induced death after irradiation with higher doses (300, 500 Gy). The intracellular glutathione (GSH) levels significantly decreased after irradiation while the combined treatment of NAC and radiation alleviated the decrease in the GSH levels. The investigations give a clue for the action mechanism of synergistic or protective effects of NAC on the cells. Due to their high resistance to ionizing radiation, the PLHC-1 cells can be effectively used as a screening tool for assessing the combined effects of radiation with toxic chemicals.

  1. N-acetyl-L-cysteine affects growth, extracellular polysaccharide production, and bacterial biofilm formation on solid surfaces.

    PubMed

    Olofsson, Ann-Cathrin; Hermansson, Malte; Elwing, Hans

    2003-08-01

    N-Acetyl-L-cysteine (NAC) is used in medical treatment of patients with chronic bronchitis. The positive effects of NAC treatment have primarily been attributed to the mucus-dissolving properties of NAC, as well as its ability to decrease biofilm formation, which reduces bacterial infections. Our results suggest that NAC also may be an interesting candidate for use as an agent to reduce and prevent biofilm formation on stainless steel surfaces in environments typical of paper mill plants. Using 10 different bacterial strains isolated from a paper mill, we found that the mode of action of NAC is chemical, as well as biological, in the case of bacterial adhesion to stainless steel surfaces. The initial adhesion of bacteria is dependent on the wettability of the substratum. NAC was shown to bind to stainless steel, increasing the wettability of the surface. Moreover, NAC decreased bacterial adhesion and even detached bacteria that were adhering to stainless steel surfaces. Growth of various bacteria, as monocultures or in a multispecies community, was inhibited at different concentrations of NAC. We also found that there was no detectable degradation of extracellular polysaccharides (EPS) by NAC, indicating that NAC reduced the production of EPS, in most bacteria tested, even at concentrations at which growth was not affected. Altogether, the presence of NAC changes the texture of the biofilm formed and makes NAC an interesting candidate for use as a general inhibitor of formation of bacterial biofilms on stainless steel surfaces.

  2. Effects of N-acetyl-L-cysteine on the membrane vesicle release and growth of respiratory pathogens.

    PubMed

    Volgers, Charlotte; Benedikter, Birke J; Grauls, Gert E; Hellebrand, Pauline H M; Savelkoul, Paul H M; Stassen, Frank R M

    2017-05-01

    Bacterial infections contribute to the disease progression of chronic obstructive pulmonary disease by stimulating mucus production in the airways. This increased mucus production and other symptoms are often alleviated when patients are treated with mucolytics such as N-acetyl-L-cysteine (NAC). Moreover, NAC has been suggested to inhibit bacterial growth. Bacteria can release membrane vesicles (MVs) in response to stress, and recent studies report a role for these proinflammatory MVs in the pathogenesis of airways disease. Yet, until now it is not clear whether NAC also affects the release of these MVs. This study set out to determine whether NAC, at concentrations reached during high-dose nebulization, affects bacterial growth and MV release of the respiratory pathogens non-typeable Haemophilus influenzae (NTHi), Moraxella catarrhalis (Mrc), Streptococcus pneumoniae (Spn) and Pseudomonas aeruginosa (Psa). We observed that NAC exerted a strong bacteriostatic effect, but also induced the release of proinflammatory MVs by NTHi, Mrc and Psa, but not by Spn. Interestingly, NAC also markedly blunted the release of TNF-α by naive macrophages in response to MVs. This suggests that the application of NAC by nebulization at a high dosage may be beneficial for patients with airway conditions associated with bacterial infections. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Facile synthesis of N-acetyl-L-cysteine capped CdHgSe quantum dots and selective determination of hemoglobin.

    PubMed

    Wang, Qingqing; Zhan, Guoqing; Li, Chunya

    2014-01-03

    Using N-acetyl-L-cysteine (NAC) as a stabilizer, well water-dispersed, high-quality and stable CdHgSe quantum dots were facilely synthesized via a simple aqueous phase method. The as-prepared NAC capped CdHgSe quantum dots were thoroughly characterized by fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and transmission electron microscopy. A novel method for the selective determination of hemoglobin (Hb) was developed based on fluorescence quenching of the NAC capped CdHgSe quantum dots. A number of key factors including pH value of phosphate buffer solution, quantum dots concentration, the adding sequence of reagents and reaction time that influence the analytical performance of the NAC capped CdHgSe quantum dots in Hb determination were investigated. Under the optimal experimental conditions, the change of fluorescence intensity (ΔI) was linearly proportional to the concentration of Hb in the range of 4.0×10(-9)-4.4×10(-7) mol L(-1) with a detection limit of 2.0×10(-9) mol L(-1). The developed method has been successfully employed to determine Hb in human urine samples. Copyright © 2013. Published by Elsevier B.V.

  4. A double-blind, placebo-controlled study of N-acetyl cysteine plus naltrexone for methamphetamine dependence.

    PubMed

    Grant, Jon E; Odlaug, Brian L; Kim, Suck Won

    2010-11-01

    Reducing both glutamatergic and dopaminergic drive in the nucleus accumbens may offer complementary mechanisms by which to reduce drug cravings. This 8-week study sought to examine the efficacy of a combination of a glutamate modulator, N-acetyl cysteine (NAC), plus the opioid antagonist, naltrexone, compared to placebo in the treatment of methamphetamine dependence. Thirty-one subjects with methamphetamine dependence (mean age 36.8 ± 7.12 years; 29% female) were randomly assigned in a 1:1 fashion to NAC plus naltrexone or placebo and returned for one post-baseline visit. The Penn Craving Scale was the primary outcome measure. Self-report methamphetamine use frequency and urine toxicology were secondary measures. NAC plus naltrexone failed to demonstrate statistically significant differences from placebo on primary and secondary outcomes. The current study failed to demonstrate greater efficacy for NAC plus naltrexone compared to placebo. Given the small sample size, the statistical power to detect significant effects of active treatment versus placebo was limited. The question of whether a larger, well-powered sample would have detected differences between NAC plus naltrexone and placebo deserves further examination. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Enzymatic production of N-acetyl-d-glucosamine from crayfish shell wastes pretreated via high pressure homogenization.

    PubMed

    Wei, Guoguang; Zhang, Alei; Chen, Kequan; Ouyang, Pingkai

    2017-09-01

    This study presents an efficient pretreatment of crayfish shell using high pressure homogenization that enables N-acetyl-d-glucosamine (GlcNAc) production by chitinase. Firstly, the chitinase from Serratia proteamaculans NJ303 was screened for its ability to degrade crayfish shell and produce GlcNAc as the sole product. Secondly, high pressure homogenization, which caused the crayfish shell to adopt a fluffy netted structure that was characterized by Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), was evaluated as the best pretreatment method. In addition, the optimal conditions of high pressure homogenization of crayfish shell were determined to be five cycles at a pressure of 400bar, which achieved a yield of 3.9g/L of GlcNAc from 25g/L of crayfish shell in a batch enzymatic reaction over 1.5h. The results showed high pressure homogenization might be an efficient method for direct utilization of crayfish shell for enzymatic production of GlcNAc. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Conversion of squid pen by Pseudomonas aeruginosa K187 fermentation for the production of N-acetyl chitooligosaccharides and biofertilizers.

    PubMed

    Wang, San-Lang; Hsu, Wan-Han; Liang, Tzu-Wen

    2010-05-07

    Pseudomonas aeruginosa K187, a protease- and chitinase-producing bacterium, exhibited protease and chitinase activity after three and five days of incubation, respectively. The protease and chitinase were both produced by using 1% squid pen powder (SPP) (w/v) as sole carbon and nitrogen source. After fermentation, the deproteinization rate of the recovered squid pen gradually increased up to 68% on the fourth day. After five days of fermentation, the production of GlcNAc, (GlcNAc)(2), (GlcNAc)(3), (GlcNAc)(4) and (GlcNAc)(5) were 1.18mg/mL, 0.76mg/mL, 1.02mg/mL, 0.93mg/mL and 0.90mg/mL, respectively. The culture supernatant of K187 also exhibited activity of enhancing vegetable growth. For Brassica chinensis Linn treated with the fifth day culture supernatant, the total weight and total length increased up to 529% and 148%, respectively, compared to the control group. With this method, the production of protease, chitinase, N-acetyl chitooligosaccharides and biofertilizers may be useful for biological applications.

  7. Chronic treatment with N-acetyl-cystein delays cellular senescence in endothelial cells isolated from a subgroup of atherosclerotic patients.

    PubMed

    Voghel, Guillaume; Thorin-Trescases, Nathalie; Farhat, Nada; Mamarbachi, Aida M; Villeneuve, Louis; Fortier, Annik; Perrault, Louis P; Carrier, Michel; Thorin, Eric

    2008-05-01

    Endothelial senescence may contribute to the pathogenesis of age-related vascular disorders. Furthermore, chronic exposure to risk factors for cardiovascular disease (CVD) accelerates the effects of chronological aging by generating stress-dependent damages, including oxidative stress, therefore promoting stress-induced premature senescence. Our objective was to determine whether a chronic treatment with an antioxidant (N-acetyl-cystein, NAC) could delay senescence of endothelial cells (EC) isolated and cultured from arterial segments of patients with severe coronary artery disease. If EC were considered as one population (n=26), chronic NAC treatment slightly shortened telomere attrition rate associated with senescence but did not significantly delay the onset of endothelial senescence. However, in a subgroup of NAC-treated EC (n=15) cellular senescence was significantly delayed, NAC decreased lipid peroxidation (HNE), activated the catalytic subunit of telomerase (hTERT) and inhibited telomere attrition. In contrast, in another subgroup of EC (n=11) characterized by initial short telomeres, no effect of NAC on HNE and high levels of DNA damages, the antioxidant was not beneficial on senescence, suggesting an irreversible stress-dependent damage. In conclusion, chronic exposure to NAC can delay senescence of diseased EC via hTERT activation and transient telomere stabilization, unless oxidative stress-associated cell damage has become irreversible.

  8. Chitooligosaccharides and N-acetyl-D-glucosamine stimulate peripheral blood mononuclear cell-mediated antitumor immune responses.

    PubMed

    Xu, Wenhua; Jiang, Changqing; Kong, Xiaoying; Liang, Ye; Rong, Mi; Liu, Wanshun

    2012-08-01

    The aim of the present study was to evaluate the anticancer effects of chitooligosaccharides (COS) and N-acetyl-D-glucosamine (NAG), as well as to investigate the possible mechanisms involved. MTT assay and flow cytometry were used to evaluate the effect of various concentrations of COS and NAG on the proliferation and differentiation of peripheral blood mononuclear cells (PBMCs). In addition, sarcoma 180 cells were transplanted into mice to establish a tumor model. COS and NAG were administered by gavage of various doses. The tumor inhibition rate, thymus and spleen indexes, natural killer (NK) cell activity, and interleukin-2 (IL-2) and interferon-γ (IFN-γ) serum levels were detected. Vascular endothelial growth factor (VEGF) expression levels, an important marker of angiogenesis, were also detected. As shown by immunohistochemistry, VEGF mRNA expression was decreased following treatment with COS and NAG, indicating that COS and NAG have an inhibitory effect on the expression of VEGF. The results from this study indicate that COS administered at a dose of 100 mg/kg and NAG at a dose of 300 mg/kg or 500 mg/kg can not only promote the differentiation of PBMCs and the secretion of IL-2 and IFN-γ, but can also inhibit the expression of VEGF mRNA in sarcoma 180 tumors. Our results show that the antitumor and immunoregulatory effects of COS and NAG are dose-dependent. Furthermore, the antitumor effect is achieved by the improvement of immunoregulation indirectly.

  9. Urinary N-acetyl-beta-D-glucosaminidase and malondialdehyde as a markers of renal damage in burned patients.

    PubMed Central

    Kang, H. K.; Kim, D. K.; Lee, B. H.; Om, A. S.; Hong, J. H.; Koh, H. C.; Lee, C. H.; Shin, I. C.; Kang, J. S.

    2001-01-01

    This study was aimed to evaluate renal dysfunction during three weeks after the burn injuries in 12 patients admitted to the Hallym University Hankang Medical Center with flame burn injuries (total body surface area, 20-40%). Parameters assessed included 24-hr urine volume, blood urea nitrogen, serum creatinine, creatinine clearance, total urinary protein, urinary microalbumin, 24-hr urinary N-acetyl-beta-D-glucosaminidase (NAG) activity, and urinary malondialdehyde (MDA). Statistical analysis was performed using repeated measures ANOVA test. The 24-hr urine volume, creatinine clearance, and urinary protein significantly increased on day 3 post-burn and fell thereafter. The urine microalbumin excretion showed two peak levels on day 0 post-burn and day 3. The 24-hr urinary NAG activity significantly increased to its maximal level on day 7 post-burn and gradually fell thereafter. The urinary MDA progressively increased during 3 weeks after the burn injury. Despite recovery of general renal function through an intensive care of burn injury, renal tubular damage and lipid peroxidation of the renal tissue suggested to persist during three weeks after the burn. Therefore, a close monitoring and intensive management of renal dysfunction is necessary to prevent burn-induced acute renal failure as well as to lower mortality in patients with major burns. PMID:11641529

  10. N-acetyl-cysteine inhibits liver oxidative stress markers in BALB/c mice infected with Leishmania amazonensis

    PubMed Central

    Gasparotto, Juciano; Kunzler, Alice; Senger, Mario Roberto; de Souza, Celeste da Silva Freitas; de Simone, Salvatore Giovanni; Bortolin, Rafael Calixto; Somensi, Nauana; Dal-Pizzol, Felipe; Moreira, José Claudio Fonseca; Abreu-Silva, Ana Lúcia; Calabrese, Kátia da Silva; Silva, Floriano Paes; Gelain, Daniel Pens

    2017-01-01

    BACKGROUND Leishmaniasis is a parasitosis caused by several species of the genus Leishmania. These parasites present high resistance against oxidative stress generated by inflammatory cells. OBJECTIVES To investigate oxidative stress and molecular inflammatory markers in BALB/c mice infected with L. amazonensis and the effect of antioxidant treatment on these parameters. METHODS Four months after infection, oxidative and inflammatory parameters of liver, kidneys, spleen, heart and lungs from BALB/c mice were assessed. FINDINGS In liver, L. amazonensis caused thiol oxidation and nitrotyrosine formation; SOD activity and SOD2 protein content were increased while SOD1 protein content decreased. The content of the cytokines IL-1β, IL-6, TNF-α, and the receptor of advanced glycation endproducts (RAGE) increased in liver. Treatment with the antioxidant N-acetyl-cysteine (20 mg/kg b.w) for five days inhibited oxidative stress parameters. MAIN CONCLUSIONS L. amazonensis induces significant alterations in the redox status of liver but not in other organs. Acute antioxidant treatment alleviates oxidative stress in liver, but it had no effect on pro-inflammatory markers. These results indicate that the pathobiology of leishmaniasis is not restricted to the cutaneous manifestations and open perspectives for the development of new therapeutic approaches to the disease, especially for liver function. PMID:28177049

  11. Mild to severe lithium-induced nephropathy models and urine N-acetyl-beta-D-glucosaminidase in rats.

    PubMed

    Ida, S; Yokota, M; Ueoka, M; Kiyoi, K; Takiguchi, Y

    2001-10-01

    Long-term treatment with lithium induces functional and/or structural disturbances in the kidneys. However, no procedure has been established for the early diagnosis of lithium intoxication. In this study, we prepared mild to severe lithium-induced nephropathy rat models and examined the usefulness of urine N-acetyl-beta-D-glucosaminidase (NAG) for the early diagnosis of lithium-induced renal insufficiency. Lithium was administered by repeated intraperitoneal injection (1, 2 and 4 mEq/kg/day for 10 days). We also measured the plasma creatinine and paraaminohippuric acid (PAH) clearance, and observed renal histological changes. Lithium pretreatment elevated the plasma creatinine level and decreased PAH clearance in a dose-dependent manner. The NAG level in the lithium 4 mEq/kg group was very high. The levels in the lithium 1 mEq/kg and 2 mEq/kg groups were almost the same and were higher than the control group. A histological examination of the kidney revealed glomerular congestion and/or atrophy and tubular expansion in all of the groups except the control group. These histological changes were dose-dependent. In conclusion, urine NAG may be useful in the early diagnosis of renal side effects caused by lithium therapy. When the urine NAG level becomes high in a patient taking lithium for bipolar disorder, the physician may need to consider lithium-induced renal insufficiency.

  12. N-Acetylated Proline-Glycine-Proline Accelerates Cutaneous Wound Healing and Neovascularization by Human Endothelial Progenitor Cells

    PubMed Central

    Kwon, Yang Woo; Heo, Soon Chul; Lee, Tae Wook; Park, Gyu Tae; Yoon, Jung Won; Jang, Il Ho; Kim, Seung-Chul; Ko, Hyun-Chang; Ryu, Youngjae; Kang, Hyeona; Ha, Chang Man; Lee, Sang Chul; Kim, Jae Ho

    2017-01-01

    Human endothelial progenitor cells (hEPCs) are promising therapeutic resources for wound repair through stimulating neovascularization. However, the hEPCs-based cell therapy has been hampered by poor engraftment of transplanted cells. In this study, we explored the effects of N-acetylated Proline-Glycine-Proline (Ac-PGP), a degradation product of collagen, on hEPC-mediated cutaneous wound healing and neovascularization. Treatment of hEPCs with Ac-PGP increased migration, proliferation, and tube-forming activity of hEPCs in vitro. Knockdown of CXCR2 expression in hEPCs abrogated the stimulatory effects of Ac-PGP on migration and tube formation. In a cutaneous wound healing model of rats and mice, topical application of Ac-PGP accelerated cutaneous wound healing with promotion of neovascularization. The positive effects of Ac-PGP on wound healing and neovascularization were blocked in CXCR2 knockout mice. In nude mice, the individual application of Ac-PGP treatment or hEPC injection accelerated wound healing by increasing neovascularization. Moreover, the combination of Ac-PGP treatment and hEPC injection further stimulated wound healing and neovascularization. Topical administration of Ac-PGP onto wound bed stimulated migration and engraftment of transplanted hEPCs into cutaneous dermal wounds. Therefore, these results suggest novel applications of Ac-PGP in promoting wound healing and augmenting the therapeutic efficacy of hEPCs. PMID:28230162

  13. Interaction of N-acetyl-4-epi-D-neuraminic acid with key enzymes of sialic acid metabolism.

    PubMed

    Gross, H J; Kovac, A; Rose, U; Watzlawick, H; Brossmer, R

    1988-06-14

    In spite of the axially orientated hydroxy group at C-4, the benzyl alpha-glycoside of N-acetyl-4-epi-D-neuraminic acid (4-epi-NeuAc) is a substrate for sialidases from Vibrio cholerae, Clostridium perfringens, and Arthrobacter ureafaciens, although to an extent which differs depending on the enzyme. Surprisingly, V. cholerae sialidase is by far the slowest acting enzyme; this is in contrast to its usual behavior. Fowl plague virus sialidase and bovine testis sialidase also cleave this glycoside slowly. 4-Epi-NeuAc is not a substrate for N-acetylneuraminic acid aldolase from C. perfringens but reversibly inhibits the enzyme with a Ki = 2.3 mM. The N-acetylneuraminic acid analogue is not converted to the corresponding CMP-glycoside by CMP-sialic acid synthase from bovine brain; however, it is an effective reversible inhibitor of the enzyme. The kinetic properties were analyzed with an assay system at pH 9 as well as an assay system at pH 7.5. The results from Dixon and Hanes plots did not agree. Therefore, no conclusions about the mechanism of the inhibition could be reached. This is the first reported sialic acid analogue which can act as an inhibitor of CMP-sialic acid synthase.

  14. Spectroscopic investigations on the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots on catalase

    NASA Astrophysics Data System (ADS)

    Sun, Haoyu; Yang, Bingjun; Cui, Erqian; Liu, Rutao

    2014-11-01

    Quantum dots (QDs) are recognized as some of the most promising semiconductor nanocrystals in biomedical applications. However, the potential toxicity of QDs has aroused wide public concern. Catalase (CAT) is a common enzyme in animal and plant tissues. For the potential application of QDs in vivo, it is important to investigate the interaction of QDs with CAT. In this work, the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots with fluorescence emission peak at 612 nm (QDs-612) on CAT was investigated by fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible (UV-vis) absorption and circular dichroism (CD) techniques. Binding of QDs-612 to CAT caused static quenching of the fluorescence, the change of the secondary structure of CAT and the alteration of the microenvironment of tryptophan residues. The association constants K were determined to be K288K = 7.98 × 105 L mol-1 and K298K = 7.21 × 105 L mol-1. The interaction between QDs-612 and CAT was spontaneous with 1:1 stoichiometry approximately. The CAT activity was also inhibited for the bound QDs-612. This work provides direct evidence about enzyme toxicity of QDs-612 to CAT in vitro and establishes a new strategy to investigate the interaction between enzyme and QDs at a molecular level, which is helpful for clarifying the bioactivities of QDs in vivo.

  15. N-acetyl-cysteine attenuates remifentanil-induced postoperative hyperalgesia via inhibiting matrix metalloproteinase-9 in dorsal root ganglia.

    PubMed

    Liu, Yue; Ni, Yuan; Zhang, Wei; Sun, Yu-E; Ma, Zhengliang; Gu, Xiaoping

    2017-02-09

    Treatment of remifentanil-induced postoperative hyperalgesia (RIH) remains a clinical challenge because the mechanisms are not fully understood. Matrix metalloproteinase-9 (MMP-9) is a key component in neuroinflammation because of its facilitation of pro-inflammatory cytokine maturation. Therefore, inhibition of MMP-9 may represent a novel therapeutic approach to the treatment of RIH. Sprague-Dawley rats were randomly divided into three groups: Control, Incision and Remifentanil. A right plantar surgical incision was performed in Group Incision, and intraoperative remifentanil (0.04 mg/kg, 0.4 ml) was infused subcutaneously for 30 min in Group Remifentanil. The results indicated that intraoperative remifentanil induced an up-regulation and activation of MMP-9 in DRGs but not spinal cords. MMP-9 was expressed primarily in DRG neurons co-expressing mu opioid receptors (MOR), and elicited interleukin-1β (IL-1β) cleavage in DRG neurons and satellite glial cells (SGCs). Intraperitoneal injection of N-acetyl-cysteine (NAC), a broadly used safe drug, significantly attenuated RIH via suppressing the activation of MMP-9 in DRGs. NAC inhibited the cleavage of IL-1β in DRGs, which is a critical substrate of MMP-9, and markedly suppressed glial activation and neuron excitability in spinal dorsal horn induced by remifentanil. These results demonstrated that NAC can effectively alleviate RIH via powerfully inhibiting MMP-9 activation in DRGs.

  16. Protein oxidation under extremely low frequency electric field in guinea pigs. Effect of N-acetyl-L-cysteine treatment.

    PubMed

    Güler, Göknur; Türközer, Zerrin; Ozgur, Elcin; Tomruk, Arin; Seyhan, Nesrin; Karasu, Cimen

    2009-03-01

    Modern age exposes humans to an increasing level of electromagnetic activity in their environment due to overhead power lines and transformers around residential areas. Studies have shown that treatment with antioxidants can suppress the oxidative damage induced by electromagnetic fields in various frequencies of the non-ionizing radiation band. In this study, we detected protein carbonyl content (PCO), advanced oxidation protein products (AOPP) in liver and 3-nitrotyrosine (3-NT) levels in plasma of guinea pigs in order to investigate the effects of N-acetyl-L-cysteine (NAC) administration on oxidative protein damage induced by power frequency electric (E) field (50 Hz, 12 kV/m, 7 days/8 h/day). We also analyzed hepatic hydroxyproline level to study protein synthesis. According to the findings of the present study, no statistically significant changes occurred in PCO, AOPP and 3-NT levels of the guinea pigs that were exposed to the E field with respect to the control group. However, liver hydroxyproline level was significantly diminished in the E field exposure group compared to the control and PCO, hydroxyproline and 3-NT levels changed significantly in the NAC-administrated groups.

  17. Induction of apoptosis in cancer cells through N-acetyl-l-leucine-modified polyethylenimine-mediated p53 gene delivery.

    PubMed

    Li, Zhiyuan; Zhang, Liu; Li, Quanshun

    2015-11-01

    Herein, N-acetyl-L-leucine-modified polyethylenimine was successfully constructed through the EDC/NHS-mediated coupling reaction and employed as vectors to accomplish p53 gene delivery using HeLa (p53wt) and PC-3 cells (p53null) as models. Compared with PEI25K, the derivatives exhibited lower cytotoxicity, protein adsorption and hemolytic activity, together with satisfactory pDNA condensation capability and gene transfection efficiency. After p53 transfection, MTT analysis confirmed that the cell proliferation was inhibited. Flow cytometric analysis showed that the derivative-mediated p53 delivery could induce stronger early apoptosis than PEI25K and Lipofectamine(2000). Further, PC-3 cells showed higher sensitivity to the exogenous p53 transfection than HeLa cells. The mechanism for inducing apoptosis was determined to be up-regulation of p53 expression at both mRNA and protein levels using RT-PCR and western blotting analysis. Expression level and activity analysis of caspase-3, -8 and -9, and mitochondrial membrane potential measurement revealed that p53 transfection mediated by these derivatives facilitated early apoptosis of tumor cells via a mitochondria-dependent apoptosis pathway. Thus, the derivatives showed potential as biocompatible carriers for realizing effective tumor gene therapy.

  18. Synthesis and macrophage activation of lentinan-mimic branched amino polysaccharides: curdlans having N-Acetyl-d-glucosamine branches.

    PubMed

    Kurita, Keisuke; Matsumura, Yuriko; Takahara, Hiroki; Hatta, Kiyoshige; Shimojoh, Manabu

    2011-06-13

    N-Acetyl-d-glucosamine branches were incorporated at the C-6 position of curdlan, a linear β-1,3-d-glucan, and the resulting nonnatural branched polysaccharides were evaluated in terms of the immunomodulation activities in comparison with lentinan, a β-1,3-d-glucan having d-glucose branches at C-6. To incorporate the amino sugar branches, we conducted a series of regioselective protection-deprotections of curdlan involving triphenylmethylation at C-6, phenylcarbamoylation at C-2 and C-4, and detriphenylmethylation. Subsequent glycosylation with a d-glucosamine-derived oxazoline, followed by deprotection gave rise to the branched curdlans with various substitution degrees. The products exhibited remarkable solubility in both organic solvents and water. Their immunomodulation activities were determined using mouse macrophagelike cells, and the secretions of both the tumor necrosis factor and nitric oxide proved to be significantly higher than those with lentinan. These results conclude that the amino sugar/curdlan hybrid materials are promising as a new type of polysaccharide immunoadjuvants useful for cancer chemotherapy.

  19. N-acetyl-cysteine inhibits liver oxidative stress markers in BALB/c mice infected with Leishmania amazonensis.

    PubMed

    Gasparotto, Juciano; Kunzler, Alice; Senger, Mario Roberto; Souza, Celeste da Silva Freitas de; Simone, Salvatore Giovanni de; Bortolin, Rafael Calixto; Somensi, Nauana; Dal-Pizzol, Felipe; Moreira, José Claudio Fonseca; Abreu-Silva, Ana Lúcia; Calabrese, Kátia da Silva; Silva, Floriano Paes; Gelain, Daniel Pens

    2017-02-01

    Leishmaniasis is a parasitosis caused by several species of the genus Leishmania. These parasites present high resistance against oxidative stress generated by inflammatory cells. To investigate oxidative stress and molecular inflammatory markers in BALB/c mice infected with L. amazonensis and the effect of antioxidant treatment on these parameters. Four months after infection, oxidative and inflammatory parameters of liver, kidneys, spleen, heart and lungs from BALB/c mice were assessed. In liver, L. amazonensis caused thiol oxidation and nitrotyrosine formation; SOD activity and SOD2 protein content were increased while SOD1 protein content decreased. The content of the cytokines IL-1β, IL-6, TNF-α, and the receptor of advanced glycation endproducts (RAGE) increased in liver. Treatment with the antioxidant N-acetyl-cysteine (20 mg/kg b.w) for five days inhibited oxidative stress parameters. L. amazonensis induces significant alterations in the redox status of liver but not in other organs. Acute antioxidant treatment alleviates oxidative stress in liver, but it had no effect on pro-inflammatory markers. These results indicate that the pathobiology of leishmaniasis is not restricted to the cutaneous manifestations and open perspectives for the development of new therapeutic approaches to the disease, especially for liver function.

  20. Dextromethorphan and caffeine as probes for simultaneous determination of debrisoquin-oxidation and N-acetylation phenotypes in children.

    PubMed

    Evans, W E; Relling, M V; Petros, W P; Meyer, W H; Mirro, J; Crom, W R

    1989-05-01

    The feasibility and reliability of simultaneously determining debrisoquin oxidation and N-acetylation phenotypes was assessed in children with use of two innocuous substrate probes given by mouth, 30 mg dextromethorphan (Pertussin ES) and 25 to 46 mg caffeine (Coca-Cola beverage). Twenty-six children and adolescents (aged 3 to 21 years) were studied three times, once with each substrate given alone and once with the two substrates given together. Urine was collected for 4 hours, and the molar urinary metabolic ratios for dextromethorphan:dextrorphan and for two caffeine metabolites (AFMU:1X) were determined by HPLC ultraviolet assays. The urinary metabolic ratios for both substrates were not significantly different when the substrates were given alone compared with when they were given together. There also was no difference in either the oxidation or acetylation phenotype assignments when the two substrates were given alone and when they were given together. No adverse effects were observed. We conclude that dextromethorphan and caffeine can be given together to simultaneously determine oxidation and acetylation phenotypes and can thereby provide an innocuous, noninvasive method for the assessment of polymorphic drug metabolism in various pediatric populations.

  1. Reaction pathway and free energy profile for papain-catalyzed hydrolysis of N-acetyl-Phe-Gly 4-nitroanilide

    PubMed Central

    Wei, Donghui; Huang, Xiaoqin; Tang, Mingsheng; Zhan, Chang-Guo

    2013-01-01

    Possible reaction pathways for papain-catalyzed hydrolysis of N-acetyl-Phe-Gly 4-nitroanilide (APGNA) have been studied by performing pseudobond first-principles quantum mechanical/molecular mechanical-free energy (QM/MM-FE) calculations. The whole hydrolysis process includes two stages: acylation and deacylation. For the acylation stage of the catalytic reaction, we have explored three possible paths (A, B, and C) and the corresponding free energy profiles along the reaction coordinates. It has been demonstrated that the most favorable reaction path in this stage is path B consisting of two reaction steps: the first step is a proton transfer to form a zwitterionic form (i.e. Cys-S−/His-H+ ion-pair), and the second step is the nucleophilic attack on the carboxyl carbon of the substrate accompanied with the dissociation of 4-nitroanilide. The deacylation stage includes the nucleophilic attack of a water molecule on the carboxyl carbon of the substrate and dissociation between the carboxyl carbon of the substrate and the sulfhydryl sulfur of Cys25 side chain. The free energy barriers calculated for the acylation and deacylation stages are 20.0 kcal/mol and 10.7 kcal/mol, respectively. Thus, the acylation is rate-limiting. The overall free energy barrier calculated for papain-catalyzed hydrolysis of APGNA is 20.0 kcal/mol, which is reasonably close to the experimentally derived activation free energy of 17.9 kcal/mol. PMID:23862626

  2. N-Acetyl-Serotonin Protects HepG2 Cells from Oxidative Stress Injury Induced by Hydrogen Peroxide

    PubMed Central

    Jiang, Jiying; Yu, Shuna; Jiang, Zhengchen; Liang, Cuihong; Yu, Wenbo; Li, Jin; Du, Xiaodong; Wang, Hailiang; Gao, Xianghong; Wang, Xin

    2014-01-01

    Oxidative stress plays an important role in the pathogenesis of liver diseases. N-Acetyl-serotonin (NAS) has been reported to protect against oxidative damage, though the mechanisms by which NAS protects hepatocytes from oxidative stress remain unknown. To determine whether pretreatment with NAS could reduce hydrogen peroxide- (H2O2-) induced oxidative stress in HepG2 cells by inhibiting the mitochondrial apoptosis pathway, we investigated the H2O2-induced oxidative damage to HepG2 cells with or without NAS using MTT, Hoechst 33342, rhodamine 123, Terminal dUTP Nick End Labeling Assay (TUNEL), dihydrodichlorofluorescein (H2DCF), Annexin V and propidium iodide (PI) double staining, immunocytochemistry, and western blot. H2O2 produced dramatic injuries in HepG2 cells, represented by classical morphological changes of apoptosis, increased levels of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), decreased activity of superoxide dismutase (SOD), and increased activities of caspase-9 and caspase-3, release of cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) from mitochondria, and loss of membrane potential (ΔΨm). NAS significantly inhibited H2O2-induced changes, indicating that it protected against H2O2-induced oxidative damage by reducing MDA levels and increasing SOD activity and that it protected the HepG2 cells from apoptosis through regulating the mitochondrial apoptosis pathway, involving inhibition of mitochondrial hyperpolarization, release of mitochondrial apoptogenic factors, and caspase activity. PMID:25013541

  3. Identification of the Enzyme Responsible for N-Acetylation of Norfloxacin by Microbacterium sp. Strain 4N2-2

    PubMed Central

    Kim, Dae-Wi; Feng, Jinhui; Chen, Huizhong; Kweon, Ohgew; Gao, Yuan; Yu, Li-Rong; Burrowes, Vanessa J.

    2013-01-01

    Microbacterium sp. 4N2-2, isolated from a wastewater treatment plant, converts the antibacterial fluoroquinolone norfloxacin to N-acetylnorfloxacin and three other metabolites. Because N-acetylation results in loss of antibacterial activity, identification of the enzyme responsible is important for understanding fluoroquinolone resistance. The enzyme was identified as glutamine synthetase (GS); N-acetylnorfloxacin was produced only under conditions associated with GS expression. The GS gene (glnA) was cloned, and the protein (53 kDa) was heterologously expressed and isolated. Optimal conditions and biochemical properties (Km and Vmax) of purified GS were characterized; the purified enzyme was inhibited by Mn2+, Mg2+, ATP, and ADP. The contribution of GS to norfloxacin resistance was shown by using a norfloxacin-sensitive Escherichia coli strain carrying glnA derived from Microbacterium sp. 4N2-2. The GS of Microbacterium sp. 4N2-2 was shown to act as an N-acetyltransferase for norfloxacin, which produced low-level norfloxacin resistance. Structural and docking analysis identified potential binding sites for norfloxacin at the ADP binding site and for acetyl coenzyme A (acetyl-CoA) at a cleft in GS. The results suggest that environmental bacteria whose enzymes modify fluoroquinolones may be able to survive in the presence of low fluoroquinolone concentrations. PMID:23104417

  4. Identification of the enzyme responsible for N-acetylation of norfloxacin by Microbacterium sp. Strain 4N2-2.

    PubMed

    Kim, Dae-Wi; Feng, Jinhui; Chen, Huizhong; Kweon, Ohgew; Gao, Yuan; Yu, Li-Rong; Burrowes, Vanessa J; Sutherland, John B

    2013-01-01

    Microbacterium sp. 4N2-2, isolated from a wastewater treatment plant, converts the antibacterial fluoroquinolone norfloxacin to N-acetylnorfloxacin and three other metabolites. Because N-acetylation results in loss of antibacterial activity, identification of the enzyme responsible is important for understanding fluoroquinolone resistance. The enzyme was identified as glutamine synthetase (GS); N-acetylnorfloxacin was produced only under conditions associated with GS expression. The GS gene (glnA) was cloned, and the protein (53 kDa) was heterologously expressed and isolated. Optimal conditions and biochemical properties (K(m) and V(max)) of purified GS were characterized; the purified enzyme was inhibited by Mn(2+), Mg(2+), ATP, and ADP. The contribution of GS to norfloxacin resistance was shown by using a norfloxacin-sensitive Escherichia coli strain carrying glnA derived from Microbacterium sp. 4N2-2. The GS of Microbacterium sp. 4N2-2 was shown to act as an N-acetyltransferase for norfloxacin, which produced low-level norfloxacin resistance. Structural and docking analysis identified potential binding sites for norfloxacin at the ADP binding site and for acetyl coenzyme A (acetyl-CoA) at a cleft in GS. The results suggest that environmental bacteria whose enzymes modify fluoroquinolones may be able to survive in the presence of low fluoroquinolone concentrations.

  5. Effect of a new de-N-acetyl-lysoglycosphingolipid on chemically-induced inflammatory bowel disease: possible mechanism of action.

    PubMed

    Tubaro, E; Santiangeli, C; Cavallo, G; Belogi, L; Guida, G; Croce, C; Modesti, A

    1993-12-01

    A new, orally active de-N-acetylated lysoglycosphingolipid (WILD20) was evaluated as antiinflammatory agent using a model of chemically-induced inflammatory bowel disease (IBD) in the rat to mimic human ulcerative colitis and Chron's disease. IBD was induced by hapten trinitrobenzenesulphonic acid (TNB). WILD20, orally administered as preventive or curative, was demonstrated to be efficacious at daily dosages of 0.1-1 mg/kg for 4-5 days. Damage scores, body weight, spleen weight, colonic tissular levels of LTB4, myeloperoxidase (MPO) and malondialdehyde (MDA) are influenced and brought into parameters of normality. Histological observation demonstrated quicker healing, better repair, reduced inflammation, and poor eosinophil degranulation. The mechanisms underlying WILD20 antiinflammatory effects were investigated: whereas WILD20 fails to show a direct effect on PKC, it reduces PKC translocation to the membrane; cellular PLA2 was consequently greatly reduced through this mechanism and thought to be responsible for WILD20 efficacy towards chemically-induced IBD.

  6. A 4-deoxy analogue of N-acetyl-D-glucosamine inhibits heparan sulphate expression and growth factor binding in vitro

    SciTech Connect

    Wijk, Xander M.R. van; Oosterhof, Arie; Broek, Sebastiaan A.M.W. van den; Griffioen, Arjan W.; Dam, Gerdy B. ten; Rutjes, Floris P.J.T.; Delft, Floris L. van; Kuppevelt, Toin H. van

    2010-09-10

    Heparan sulphate (HS) is a long, linear polysaccharide, which has a basic backbone of -{beta}1-4GlcA-{alpha}1-4GlcNAc- units. The involvement of HS in many steps of tumourigenesis, including growth and angiogenesis, makes it an appealing target for cancer therapy. To target the biosynthesis of HS by interfering with its chain elongation, a 4-deoxy analogue of N-acetyl-D-glucosamine (4-deoxy-GlcNAc) was synthesized. Using immunocytochemistry and agarose gel electrophoresis it was shown that incubation with the 4-deoxysugar resulted in a dose dependent reduction of HS expression of MV3 melanoma cells, 1 mM resulting in an almost nullified HS expression. The parent sugar GlcNAc had no effect. 4-deoxysugar treated cells were viable and proliferated at the same rate as control cells. Other glycan structures appeared to be only mildly affected, as staining by various lectins was generally not or only modestly inhibited. At 1 mM of the 4-deoxysugar, the capacity of cells to bind the HS-dependent pro-angiogenic growth factors FGF-2 and VEGF was greatly compromised. Using an in vitro angiogenesis assay, 4-deoxysugar treated endothelial cells showed a sharp reduction of FGF-2-induced sprout formation. Combined, these data indicate that an inexpensive, easily synthesized, water-soluble monosaccharide analogue can interfere with HS expression and pro-angiogenic growth factor binding.

  7. Premature senescence of endothelial cells upon chronic exposure to TNFα can be prevented by N-acetyl cysteine and plumericin

    PubMed Central

    Khan, Shafaat Y.; Awad, Ezzat M.; Oszwald, Andre; Mayr, Manuel; Yin, Xiaoke; Waltenberger, Birgit; Stuppner, Hermann; Lipovac, Markus; Uhrin, Pavel; Breuss, Johannes M.

    2017-01-01

    Cellular senescence is characterized by a permanent cell-cycle arrest and a pro-inflammatory secretory phenotype, and can be induced by a variety of stimuli, including ionizing radiation, oxidative stress, and inflammation. In endothelial cells, this phenomenon might contribute to vascular disease. Plasma levels of the inflammatory cytokine tumor necrosis factor alpha (TNFα) are increased in age-related and chronic conditions such as atherosclerosis, rheumatoid arthritis, psoriasis, and Crohn’s disease. Although TNFα is a known activator of the central inflammatory mediator NF-κB, and can induce the intracellular generation of reactive oxygen species (ROS), the question whether TNFα can induce senescence has not been answered conclusively. Here, we investigated the effect of prolonged TNFα exposure on the fate of endothelial cells and found that such treatment induced premature senescence. Induction of endothelial senescence was prevented by the anti-oxidant N-acetyl cysteine, as well as by plumericin and PHA-408, inhibitors of the NF-κB pathway. Our results indicated that prolonged TNFα exposure could have detrimental consequences to endothelial cells by causing senescence and, therefore, chronically increased TNFα levels might possibly contribute to the pathology of chronic inflammatory diseases by driving premature endothelial senescence. PMID:28045034

  8. AsnB, regulated by diffusible signal factor and global regulator Clp, is involved in aspartate metabolism, resistance to oxidative stress and virulence in Xanthomonas oryzae pv. oryzicola.

    PubMed

    Qian, Guoliang; Liu, Chunhui; Wu, Guichun; Yin, Fangqun; Zhao, Yancun; Zhou, Yijing; Zhang, Yanbing; Song, Zhiwei; Fan, Jiaqin; Hu, Baishi; Liu, Fengquan

    2013-02-01

    Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak in rice, which is a destructive disease worldwide. Xoc virulence factors are regulated by diffusible signal factor (DSF) and the global regulator Clp. In this study, we have demonstrated that asnB (XOC_3054), encoding an asparagine synthetase, is a novel virulence-related gene regulated by both DSF and Clp in Xoc. A sequence analysis revealed that AsnB is highly conserved in Xanthomonas. An asnB mutation in Xoc dramatically impaired pathogen virulence and growth rate in host rice, but did not affect the ability to trigger the hypersensitive response in nonhost (plant) tobacco. Compared with the wild-type strain, the asnB deletion mutant was unable to grow in basic MMX (-) medium (a minimal medium without ammonium sulphate as the nitrogen source) with or without 10 tested nitrogen sources, except asparagine. The disruption of asnB impaired pathogen resistance to oxidative stress and reduced the transcriptional expression of oxyR, katA and katG, which encode three important proteins responsible for hydrogen peroxide (H(2)O(2)) sensing and detoxification in Xanthomonas in the presence of H(2)O(2), and nine important known Xoc virulence-related genes in plant cell-mimicking medium. Furthermore, the asnB mutation did not affect extracellular protease activity, extracellular polysaccharide production, motility or chemotaxis. Taken together, our results demonstrate the role of asnB in Xanthomonas for the first time. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  9. Is Aspartate an Excitatory Neurotransmitter?

    PubMed Central

    Herring, Bruce E.; Silm, Katlin

    2015-01-01

    Recent evidence has resurrected the idea that the amino acid aspartate, a selective NMDA receptor agonist, is a neurotransmitter. Using a mouse that lacks the glutamate-selective vesicular transporter VGLUT1, we find that glutamate alone fully accounts for the activation of NMDA receptors at excitatory synapses in the hippocampus. This excludes a role for aspartate and, by extension, a recently proposed role for the sialic acid transporter sialin in excitatory transmission. SIGNIFICANCE STATEMENT It has been proposed that the amino acid aspartate serves as a neurotransmitter. Although aspartate is a selective agonist for NMDA receptors, we find that glutamate alone fully accounts for neurotransmission at excitatory synapses in the hippocampus, excluding a role for aspartate. PMID:26180193

  10. Vibrational Signatures of Isomeric Lithiated N-acetyl-D-hexosamines by Gas-Phase Infrared Multiple-Photon Dissociation (IRMPD) Spectroscopy

    NASA Astrophysics Data System (ADS)

    Tan, Yanglan; Zhao, Ning; Liu, Jinfeng; Li, Pengfei; Stedwell, Corey N.; Yu, Long; Polfer, Nicolas C.

    2017-01-01

    Three lithiated N-acetyl-D-hexosamine (HexNAc) isomers, N-acetyl-D-glucosamine (GlcNAc), N-acetyl-D-galactosamine (GalNAc), and N-acetyl-D-mannosamine (ManNAc) are investigated as model monosaccharide derivatives by gas-phase infrared multiple-photon dissociation (IRMPD) spectroscopy. The hydrogen stretching region, which is attributed to OH and NH stretching modes, reveals some distinguishing spectral features of the lithium-adducted complexes that are useful in terms of differentiating these isomers. In order to understand the effect of lithium coordination on saccharide structure, and therefore anomericity, chair configuration, and hydrogen bonding networks, the conformational preferences of lithiated GlcNAc, GalNAc, and ManNAc are studied by comparing the experimental measurements with density functional theory (DFT) calculations. The experimental results of lithiated GlcNAc and GalNAc show a good match to the theoretical spectra of low-energy structures adopting a 4 C 1 chair conformation, consistent with this motif being the dominant conformation in condensed-phase monosaccharides. The epimerization effect upon going to lithiated ManNAc is significant, as in this case the 1 C 4 chair conformers give a more compelling match with the experimental results, consistent with their lower calculated energies. A contrasting computational study of these monosaccharides in their neutral form suggests that the lithium cation coordination with Lewis base oxygens can play a key role in favoring particular structural motifs (e.g., a 4 C 1 versus 1 C 4 ) and disrupting hydrogen bond networks, thus exhibiting specific IR spectral features between these closely related lithium-chelated complexes.

  11. Role of N-acetyl-seryl-aspartyl-lysyl-proline in the antifibrotic and anti-inflammatory effects of the angiotensin-converting enzyme inhibitor captopril in hypertension.

    PubMed

    Peng, Hongmei; Carretero, Oscar A; Liao, Tang-Dong; Peterson, Edward L; Rhaleb, Nour-Eddine

    2007-03-01

    Angiotensin-converting enzyme inhibitors (ACEis) are known to have antifibrotic effects on the heart and kidney in both animal models and humans. N-acetyl-seryl-aspartyl-lysyl-proline is a natural inhibitor of proliferation of hematopoietic stem cells and a natural substrate of ACEi that was reported to prevent cardiac and renal fibrosis in vivo. However, it is not clear whether N-acetyl-seryl-aspartyl-lysyl-proline participates in the antifibrotic effects of ACEi. To clarify this issue, we used a model of aldosterone-salt-induced hypertension in rats treated with the ACEi captopril either alone or combined with an anti-N-acetyl-seryl-aspartyl-lysyl-proline monoclonal antibody. These hypertensive rats had the following: (1) left ventricular and renal hypertrophy, as well as increased collagen deposition in the left ventricular and the kidney; (2) glomerular matrix expansion; and (3) increased ED1-positive cells and enhanced phosphorylated-p42/44 mitogen-activated protein kinase in the left ventricle and kidney. The ACEi alone significantly lowered systolic blood pressure (P=0.008) with no effect on organ hypertrophy; it significantly lowered left ventricular collagen content, and this effect was blocked by the monoclonal antibody as confirmed by the histological data. As expected, the ACEi significantly decreased renal collagen deposition and glomerular matrix expansion, and these effects were attenuated by the monoclonal antibody. Likewise, the ACEi significantly decreased ED1-positive cells and inhibited p42/44 mitogen-activated protein kinase phosphorylation in the left ventricle and kidney, and these effects were blocked by the monoclonal antibody. We concluded that in aldosterone-salt-induced hypertension, the antifibrotic effect of ACEi on the heart and kidney, is partially mediated by N-acetyl-seryl-aspartyl-lysyl-proline, resulting in decreased inflammatory cell infiltration and p42/44 mitogen-activated protein kinase activation.

  12. Vibrational Signatures of Isomeric Lithiated N-acetyl-D-hexosamines by Gas-Phase Infrared Multiple-Photon Dissociation (IRMPD) Spectroscopy

    NASA Astrophysics Data System (ADS)

    Tan, Yanglan; Zhao, Ning; Liu, Jinfeng; Li, Pengfei; Stedwell, Corey N.; Yu, Long; Polfer, Nicolas C.

    2017-03-01

    Three lithiated N-acetyl-D-hexosamine (HexNAc) isomers, N-acetyl-D-glucosamine (GlcNAc), N-acetyl-D-galactosamine (GalNAc), and N-acetyl-D-mannosamine (ManNAc) are investigated as model monosaccharide derivatives by gas-phase infrared multiple-photon dissociation (IRMPD) spectroscopy. The hydrogen stretching region, which is attributed to OH and NH stretching modes, reveals some distinguishing spectral features of the lithium-adducted complexes that are useful in terms of differentiating these isomers. In order to understand the effect of lithium coordination on saccharide structure, and therefore anomericity, chair configuration, and hydrogen bonding networks, the conformational preferences of lithiated GlcNAc, GalNAc, and ManNAc are studied by comparing the experimental measurements with density functional theory (DFT) calculations. The experimental results of lithiated GlcNAc and GalNAc show a good match to the theoretical spectra of low-energy structures adopting a 4 C 1 chair conformation, consistent with this motif being the dominant conformation in condensed-phase monosaccharides. The epimerization effect upon going to lithiated ManNAc is significant, as in this case the 1 C 4 chair conformers give a more compelling match with the experimental results, consistent with their lower calculated energies. A contrasting computational study of these monosaccharides in their neutral form suggests that the lithium cation coordination with Lewis base oxygens can play a key role in favoring particular structural motifs (e.g., a 4 C 1 versus 1 C 4 ) and disrupting hydrogen bond networks, thus exhibiting specific IR spectral features between these closely related lithium-chelated complexes.

  13. A modeling study for structure features of β-N-acetyl-D-hexosaminidase from Ostrinia furnacalis and its novel inhibitor allosamidin: species selectivity and multi-target characteristics.

    PubMed

    Wang, Yanli; Liu, Tian; Yang, Qing; Li, Zhong; Qian, Xuhong

    2012-04-01

    Insect β-N-acetyl-D-hexosaminidase, a chitin degrading enzyme, is physiologically important during the unique life cycle of the insect. OfHex1, a β-N-acetyl-D-hexosaminidase from the insect, Ostrinia furna, which was obtained by our laboratory (Gen Bank No.: ABI81756.1), was studied by molecular modeling as well as by molecular docking with its inhibitor, allosamidin. 3D model of OfHex1 was built through the ligand-supported homology modeling approach. The binding modes of its substrate and inhibitor were proposed through docking and cluster analysis. The pocket's size and shape of OfHex1 differ from that of human β-N-acetyl-D-hexosaminidase, which determined that allosamidin can selectively inhibit OfHex1 instead of human β-N-acetyl-D-hexosaminidase. Moreover, the multi-target characteristics of allosamidin that inhibit enzymes from different families, OfHex1 (EC 3.2.1.52; GH20) and chitinase (EC 3.2.1.14; GH18), were compared. The common -1/+1 sugar-binding site of chitinase and OfHex1, and the -2/-3 sugar-binding site in chitinase contribute to the binding of allosamidin. This work, at molecular level, proved that OfHex1 could be a potential species-specific target for novel green pesticide design and also provide the possibility to develop allosamidin or its derivatives as a new type of insecticide to 'hit two birds with one stone', which maybe become a novel strategy in pest control. © 2011 John Wiley & Sons A/S.

  14. Genetically Epilepsy-Prone Rats Have Increased Brain Regional Activity of an Enzyme Which Liberates Glutamate from N-acetyl-aspartyl-glutamate

    DTIC Science & Technology

    1992-01-01

    genetically epilepsy -prone iats "was 11-26% greater than control in brain regions, including the amygdala, hippocarrpus and cerebellum, as well as the...9 -0 3 Genetically epilepsy -prone rats have increased brain regional activity of an enzyme which liberates glutamate from N-acetyl-aspartyl...in genctically epilepsy -prone rats was 11-~261; greater than control in brain regions. including the amygdala. hippocampus and cerebellum, as well as

  15. N-Acetyl-L-Cysteine inhibits the development of glucose intolerance and hepatic steatosis in diabetes-prone mice

    PubMed Central

    Falach-Malik, Alona; Rozenfeld, Hava; Chetboun, Moria; Rozenberg, Konstantin; Elyasiyan, Uriel; Sampson, Sanford R; Rosenzweig, Tovit

    2016-01-01

    Oxidative stress is associated with different pathological conditions, including glucose intolerance and type 2 diabetes (T2D), however studies had failed to prove the benefits of antioxidants in T2D. Aim: On the assumption that the failure to demonstrate such anti-diabetic effects is a result of sub-optimal or excessive antioxidant dosage, we aimed to clarify the dose-response effect of the antioxidant N-Acetyl-L-Cysteine (NAC) on the progression of T2D in-vivo. Methods: Experiments were conducted on KK-Ay mice and HFD-fed mice given NAC at different concentrations (200-1800 and 60-600 mg/kg/day, respectively). Glucose and insulin tolerance tests were performed and plasma insulin and lipid peroxidation were measured. Insulin signaling pathway was followed in muscle and liver. Hepatic TG accumulation and mRNA expression of genes involved in glucose metabolism were measured. Results: While 600-1800 mg/kg/day NAC all improved glucose tolerance in KK-Ay mice, only the 1200 mg/kg/day treatment increased insulin sensitivity. Hepatic function was not affected, however; microsteatosis rather than macrosteatosis was observed in NAC-treated mice compared to control. Glucose tolerance was improved in NAC-treated HFD-fed mice as well; the best results obtained with a dose of 400 mg NAC/kg/day. This was followed by lower weight gain and hepatic TG. Plasma lipid peroxidation was not correlated with the glucose-lowering effects of NAC in either model. Conclusion: Identification of the optimal dose of NAC and the population that would benefit the most from such intervention is essential in order to apply preventive and/or therapeutic use of NAC and similar agents in the future. PMID:27725855

  16. Electrochemical sensing of mesalazine and its N-acetylated metabolite in biological samples using functionalized carbon nanotubes.

    PubMed

    Nigović, Biljana; Sadiković, Mirela; Jurić, Sandra

    2016-01-15

    A rapid analytical method without the time-consuming separation step was developed to simultaneously determine mesalazine and its N-acetylated metabolite. A simply designed electrochemical sensor with functionalized carbon nanotubes in a Nafion matrix was constructed for this purpose. The presence of the nanocomposite modifier on the electrode surface significantly affects the voltammetric response of target analytes. The morphology of the modified surface was investigated by scanning electron microscopy. The effect of modifier amount on the sensor performance was investigated in order to obtain the most favorable response of mesalazine since it was found in lower concentration limits in real samples then its metabolite due to the rapid drug elimination and the slightly slower renal metabolite excretion. Under optimal conditions, the anodic peak currents measured by square-wave voltammetry increased linearly after short accumulation of 30s in the range of 5.0×10(-8)-2.5×10(-6)M and 1.0×10(-7)-5.0×10(-6)M for drug and metabolite, respectively. In addition to stable response, the sensor has excellent performance associated with high sensitivity (2.33×10(7) and 8.37×10(6)µAM(-1) for drug and metabolite, respectively). The synergistic effect of the carbon nanotubes and Nafion polymer film yielded detection limit of 1.2×10(-8)M for mesalazine and 2.6×10(-8)M for its metabolite that is comparable to known chromatographic methods. Due to the easy preparation and regeneration, the proposed sensor opens new opportunity for fast, simple and sensitive analysis of drug and its metabolite in human serum samples as well as direct quantification of mesalazine in delayed-release formulations.

  17. Development and characterization of new and scalable topical formulations containing N-acetyl-d-glucosamine-loaded solid lipid nanoparticles.

    PubMed

    Marto, Joana; Sangalli, Cecilia; Capra, Priscilla; Perugini, Paola; Ascenso, Andreia; Gonçalves, Lídia; Ribeiro, Helena

    2017-11-01

    N-Acetyl-d-glucosamine (NAG) has been recently considered for topical treatment of hyperpigmentation disorders due to its inhibitory effect on thyrosinase enzymes in melanocytes. NAG is a precursor of hyaluronic acid, increasing its amount in skin, and consequently, preserving the skin hydration and elasticity. It may also act as an emulsion stabilizer. Solid lipid nanoparticles (SLN) are advanced delivery systems successfully used in pharmaceutical and cosmetic formulations for the improvement of active molecules penetration into the skin. Therefore, this work aimed to develop and characterize stable and scalable topical formulations containing NAG-loaded SLN. NAG was incorporated in SLN which were prepared by two high shear homogenizers and characterized regarding its morphology and particle size by transmission electron microscopy and photon correlation spectroscopy, respectively. Oil emulgel and hydrogel were used as carriers of NAG-loaded SLN. Several parameters were evaluated, including the droplet size distribution, rheology, pH and topical delivery by different techniques. It was observed that SLN size was significantly dependent on NAG incorporation and homogenization process. Most tested SLN parameters appeared to be quite suitable, that is, spherical and well-defined SLN with approximately 258 nm and -30 mV. Hereafter, both gels containing SLN presented a pseudoplastic flow. Emulgel formulation containing NAG-loaded SLN allowed a higher NAG permeation through the SC compared to the respective control (about 0.8 μgcm(-2 )h(-1)). According to the results obtained, it can be suggested that NAG acts as an emulsion stabilizer. This stabilization was also particularly dependent on the homogenizer type which is quite important for scale-up process. This study demonstrated the potential of scalable SLN formulations to improve NAG topical delivery contributing to the improvement of skin properties on several skin disorders.

  18. Quantitative LC-MS/MS determination of flupirtine, its N-acetylated and two mercapturic acid derivatives in man.

    PubMed

    Scheuch, Eberhard; Methling, Karen; Bednarski, Patrick J; Oswald, Stefan; Siegmund, Werner

    2015-01-01

    The non-opiate analgesic drug flupirtine was shown in vitro to undergo hydrolysis followed by N-acetylation to form D13223, glucuronidation and conjugation with glutathione to form the stable mercapturic acid derivatives M-424 and M-466. To quantify flupirtine and its metabolites in samples obtained in a clinical study in healthy subjects selected on their genotype of NAT2, UGT1A1 and GSTP1, two LC-MS/MS methods were developed. The validation range for flupirtine and D-13223 in serum was 0.5-500 ng/ml. For urine and feces, the validation ranges for flupirtine and D-13223 were 20-5000 ng/ml and 5.0-5000 ng/ml, respectively. M-424 and M-466 could be quantified in urine between 5.0 and 5000 ng/ml. Free flupirtine and D-13223 were separated from serum, urine and feces with liquid-liquid extraction. For flupirtine and D-13223, the chromatography was performed on a XTerra C18 column isocratically with a mobile phase consisting of ammonium formate buffer (pH 3.5mM) and acetonitrile (50:50; v/v), for M-466 and M-424 a Synergi(®) Fusion-RP column was used and a linear gradient method with water/HCOOH (pH 3) and acetonitrile. The mass spectrometer operated both with electro spray ionization in positive multiple reaction monitoring mode. The developed methods fulfilled the current FDA criteria on bioanalytical method validation for accuracy (error: -16.9 to 11.2%), precision (1.2-13.4%), recovery, stability and matrix effects over the observed analytical range. Thus, the methods were suitable to quantify flupirtine absorption and metabolic disposition in man after single intravenous and oral dosing (100mg) and repeated oral administration (400mg once daily). Copyright © 2014 Elsevier B.V. All rights reserved.

  19. N-acetyl cysteine prolonged the developmental ability of mouse two-cell embryos against oxidative stress at refrigerated temperatures.

    PubMed

    Horikoshi, Yuka; Takeo, Toru; Nakagata, Naomi

    2016-06-01

    Cold storage of two-cell embryos at refrigerated temperatures is a useful means to ship genetically engineered mice. We previously reported that M2 medium maintained the developmental ability of two-cell embryos for 48 h at 4 °C, and offspring were obtained from embryos transported by a courier service under refrigerated temperatures. The limitation of 48 h practically restricts the shipping destination of the embryos. To enhance the applicability of the cold-storage technique, prolonging the time to maintain developmental ability of the embryos is required. Oxidative stress may be a cause of the declining developmental ability of cold-stored embryos. However, the effect of oxidative stress on developmental ability of embryos has not been investigated. We examined intracellular glutathione (GSH) levels of cold-stored two-cell embryos to evaluate the effect of oxidative and investigated the efficacy of adding N-acetyl cysteine (NAC) to the preservation medium on the developmental ability of cold-stored embryos and transported two-cell embryos at refrigerated temperatures. Intracellular GSH levels of two-cell embryos decreased by cold storage for longer than 72 h, whereas NAC recovered this reduction and improved the developmental ability of embryos cold-stored for 96 h. In the transport experiment, the developmental rate of transported two-cell embryos to offspring was increased by adding NAC to the preservation medium. We found that NAC prolonged the storage period of two-cell embryos and maintained the developmental ability by alleviating the reduction of intracellular GSH. These findings will improve the technique of cold-storage of two-cell embryos to facilitate efficient transport of genetically engineered mice worldwide. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. N-Acetyl-l-cysteine enhances ex-vivo amplification of deciduous teeth dental pulp stem cells.

    PubMed

    Debeljak Martacic, Jasmina; Borozan, Suncica; Radovanovic, Anita; Popadic, Dusan; Mojsilovic, Slavko; Vucic, Vesna; Todorovic, Vera; Kovacevic Filipovic, Milica

    2016-10-01

    Obtaining high number of stem cells is of interest for cell based therapies. N-Acetyl-l-cysteine (NAC) acts as a source of sulfhydryl groups and an anti-oxidative agent. The aim of this study was to test different NAC concentration on proliferation and differentiation of deciduous teeth dental pulp stem cells (DTSCs) in vitro as well as to define the possible underlining mechanism of its effect. Number of viable, apoptotic and senescent DTSCs was determined after addition of NAC (0.1mM, 1.0mM, 2.0mM). Also, cell cycle analysis, HIF1-α expression, LDH isoenzymes, superoxide-dismutase (SOD) and catalase (CAT) activity, sulfhydryl groups content, the level of lipids' and proteins' oxidative damage and differentiation capacity of NAC treated DTSCs was determined. DTSCs expressed HIF-1α in all conditions. The lowest NAC dose (0.1mM) increased the number of DTSCs by one fifth comparing to the control, most likely stimulating entry of cells into S phase of cell cycle and enhancing the activity of LDH5 isoenzyme. The highest NAC dose (2mM) inhibited DTSCs proliferation. Also, DTSCs had the lowest level of oxidative damage with 0.1mM NAC. All tested NAC concentrations enhanced DTSCs osteo-chondrogenesis. The lowest NAC dose exerted significant positive effect on DTSCs proliferation as well as antioxidative protection creating beneficial environment for stem cells in vitro cultivation especially when their clinical use is important for stimulation of osteo-chondrogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Attenuating effect of N-acetyl-L-cysteine against acute cocaine toxicity in rat C6 astroglial cells.

    PubMed

    Badisa, Ramesh B; Goodman, Carl B; Fitch-Pye, Cheryl A

    2013-08-01

    Astroglial cells are one of the most abundant cell types in the mammalian brain functioning in neuronal survival and in maintenance of fundamental patterns of circuitry. To date, no study has been conducted regarding the short-term impact of cocaine on these cells in cultures. The present study aimed to investigate acute cocaine (1 h) treatment on cell viability in rat C6 astroglial cells. In addition, the potential effect of N-acetyl-L-cysteine (NAC) against cocaine-induced toxicity was studied. It was observed that 1 h of acute cocaine exposure at 2, 3 and 4 mM caused a dose-dependent decrease in cell viability with an LC50 of 2.857 mM. Furthermore, cocaine treatment caused a decrease in glutathione (GSH) levels in the cells. It was found that cocaine did not exhibit pro-oxidant activity during its exposure to cells. Acute cocaine exposure did not induce nitric oxide (NO) release in the cells. A 5-point (1-5 mM) dose-response curve of NAC clearly indicated no adverse effect on astroglial cell viability. Pretreatment of cells with 5 mM NAC for 30 min, followed by its discard, and exposure to cocaine (2-4 mM) for 1 h protected cells against cytotoxicity by 90%. Treatment of cells with NAC-cocaine mixture rendered 100% protection. Further investigations revealed that the protection by NAC was through the increased GSH levels in the cells. Our results indicate that decreased GSH levels may represent one of the underlying pathologies of cell death and that antioxidant compounds which increase the GSH production could protect against cocaine-induced toxicity by promoting a pro-survival role in astroglial cells.

  2. Engineering of Corynebacterium glutamicum for growth and L-lysine and lycopene production from N-acetyl-glucosamine.

    PubMed

    Matano, Christian; Uhde, Andreas; Youn, Jung-Won; Maeda, Tomoya; Clermont, Lina; Marin, Kay; Krämer, Reinhard; Wendisch, Volker F; Seibold, Gerd M

    2014-06-01

    Sustainable supply of feedstock has become a key issue in process development in microbial biotechnology. The workhorse of industrial amino acid production Corynebacterium glutamicum has been engineered towards utilization of alternative carbon sources. Utilization of the chitin-derived aminosugar N-acetyl-glucosamine (GlcNAc) for both cultivation and production with C. glutamicum has hitherto not been investigated. Albeit this organism harbors the enzymes N-acetylglucosamine-6-phosphatedeacetylase and glucosamine-6P deaminase of GlcNAc metabolism (encoded by nagA and nagB, respectively) growth of C. glutamicum with GlcNAc as substrate was not observed. This was attributed to the lack of a functional system for GlcNAc uptake. Of the 17 type strains of the genus Corynebacterium tested here for their ability to grow with GlcNAc, only Corynebacterium glycinophilum DSM45794 was able to utilize this substrate. Complementation studies with a GlcNAc-uptake deficient Escherichia coli strain revealed that C. glycinophilum possesses a nagE-encoded EII permease for GlcNAc uptake. Heterologous expression of the C. glycinophilum nagE in C. glutamicum indeed enabled uptake of GlcNAc. For efficient GlcNac utilization in C. glutamicum, improved expression of nagE with concurrent overexpression of the endogenous nagA and nagB genes was found to be necessary. Based on this strategy, C. glutamicum strains for the efficient production of the amino acid L-lysine as well as the carotenoid lycopene from GlcNAc as sole substrate were constructed.

  3. Induction of germ tube formation by N-acetyl-D-glucosamine in Candida albicans: uptake of inducer and germinative response.

    PubMed Central

    Mattia, E; Carruba, G; Angiolella, L; Cassone, A

    1982-01-01

    A number of strains of Candida albicans were tested for germ tube formation after induction by N-acetyl-D-glucosamine (GlcNAc) and other simple (proline, glucose plus glutamine) or complex (serum) compounds. A proportion of strains (high responders) were induced to form germ tubes evolving to true hyphae by GlcNAc alone or by proline or glucose plus glutamine mixture. The majority of strains were low responders because they could be induced only by serum or GlcNAc-serum medium. Two strains were found to be nonresponders: they grew as pseudohyphae in serum. Despite minor quantitative differences, all strains efficiently utilized GlcNAc for growth under the yeast form at 28 degrees C. They also had comparable active, inducible, and constitutive uptake systems for GlcNAc. During germ tube formation in GlcNAc, the inducible uptake system was modulated, as expected from induction and decay of GlcNAc kinase. Uranyl acetate, at a concentration of 0.01 mM, inhibited both GlcNAc uptake and germ tube formation and was reversed by phosphates. Germinating and nongerminating cells differed in the rapidity and extent of GlcNAc incorporation into acid-insoluble and alkali-acid-insoluble cell fractions. During germ tube formation induced by proline, GlcNAc was almost totally incorporated into the acid-insoluble fraction after 60 min. Moreover, hyphal development on induction by either GlcNAc or proline was characterized by an apparent "uncoupling" between protein and polysaccharide metabolism, the ratio between the two main cellular constituents falling from more than 1 to less than 0.5 after 270 min of development. The data suggest that utilization of the inducer for wall synthesis is a determinant of germ tube formation C. albicans but that the nature and extent of inducer uptake is not a key event for this phenomenon to occur. PMID:6752114

  4. Neuroprotective effects of N-acetyl-cysteine and acetyl-L-carnitine after spinal cord injury in adult rats.

    PubMed

    Karalija, Amar; Novikova, Liudmila N; Kingham, Paul J; Wiberg, Mikael; Novikov, Lev N

    2012-01-01

    Following the initial acute stage of spinal cord injury, a cascade of cellular and inflammatory responses will lead to progressive secondary damage of the nerve tissue surrounding the primary injury site. The degeneration is manifested by loss of neurons and glial cells, demyelination and cyst formation. Injury to the mammalian spinal cord results in nearly complete failure of the severed axons to regenerate. We have previously demonstrated that the antioxidants N-acetyl-cysteine (NAC) and acetyl-L-carnitine (ALC) can attenuate retrograde neuronal degeneration after peripheral nerve and ventral root injury. The present study evaluates the effects of NAC and ALC on neuronal survival, axonal sprouting and glial cell reactions after spinal cord injury in adult rats. Tibial motoneurons in the spinal cord were pre-labeled with fluorescent tracer Fast Blue one week before lumbar L5 hemisection. Continuous intrathecal infusion of NAC (2.4 mg/day) or ALC (0.9 mg/day) was initiated immediately after spinal injury using Alzet 2002 osmotic minipumps. Neuroprotective effects of treatment were assessed by counting surviving motoneurons and by using quantitative immunohistochemistry and Western blotting for neuronal and glial cell markers 4 weeks after hemisection. Spinal cord injury induced significant loss of tibial motoneurons in L4-L6 segments. Neuronal degeneration was associated with decreased immunostaining for microtubular-associated protein-2 (MAP2) in dendritic branches, synaptophysin in presynaptic boutons and neurofilaments in nerve fibers. Immunostaining for the astroglial marker GFAP and microglial marker OX42 was increased. Treatment with NAC and ALC rescued approximately half of the motoneurons destined to die. In addition, antioxidants restored MAP2 and synaptophysin immunoreactivity. However, the perineuronal synaptophysin labeling was not recovered. Although both treatments promoted axonal sprouting, there was no effect on reactive astrocytes. In contrast, the

  5. N-Acetyl-L-cysteine enhances apoptosis through inhibition of nuclear factor-kappaB in hypoxic murine embryonic fibroblasts.

    PubMed

    Qanungo, Suparna; Wang, Mi; Nieminen, Anna-Liisa

    2004-11-26

    In this study, we investigated the role of reduced glutathione (GSH) and nuclear factor-kappaB (NFkappaB) in hypoxia-induced apoptosis. Hypoxia caused p53-dependent apoptosis in murine embryonic fibroblasts transfected with Ras and E1A. N-Acetyl-l-cysteine (NAC) but not other antioxidants, such as the vitamin E analog trolox and epigallocatechin-3-gallate, enhanced hypoxia-induced caspase-3 activation and apoptosis. NAC also enhanced hypoxia-induced apoptosis in two human cancer cell lines, MIA PaCa-2 pancreatic cancer cells and A549 lung carcinoma cells. In murine embryonic fibroblasts, all three antioxidants blocked hypoxia-induced reactive oxygen species formation. NAC did not enhance hypoxia-induced cytochrome c release but did enhance poly-(ADP ribose) polymerase cleavage, indicating that NAC acted at a post-mitochondrial level. NAC-mediated enhancement of apoptosis was mimicked by incubating cells with GSH monoester, which increased intracellular GSH similarly to NAC. Hypoxia promoted degradation of an inhibitor of kappaB(IkappaBalpha), NFkappaB-p65 translocation into the nucleus, NFkappaB binding to DNA, and subsequent transactivation of NFkappaB, which increased X chromosome-linked inhibitor of apoptosis protein levels. NAC failed to block degradation by IkappaBalpha and sequestration of the p65 subunit of NFkappaB to the nucleus. However, NAC did abrogate hypoxia-induced NFkappaB binding to DNA, NFkappaB-dependent gene expression, and induction of X chromosome-linked inhibitor of apoptosis protein. In conclusion, NAC enhanced hypoxic apoptosis by a mechanism apparently involving GSH-dependent suppression of NFkappaB transactivation.

  6. MRI characterization of cobalt dichloride-N-acetyl cysteine (C4) contrast agent marker for prostate brachytherapy

    PubMed Central

    Lim, Tze Yee; Stafford, R Jason; Kudchadker, Rajat J; Sankaranarayanapillai, Madhuri; Ibbott, Geoffrey; Rao, Arvind; Martirosyan, Karen S; Frank, Steven J

    2014-01-01

    Brachytherapy, a radiotherapy technique for treating prostate cancer, involves the implantation of numerous radioactive seeds into the prostate. While the implanted seeds can be easily identified on a CT image, distinguishing the prostate and surrounding soft tissues is not as straightforward. Magnetic Resonance Imaging (MRI) offers superior anatomical delineation, but the seeds appear as dark voids and are difficult to identify, thus creating a conundrum. Cobalt dichloride-N-acetyl-cysteine (C4) has previously been shown to be promising as an encapsulated contrast agent marker. We performed spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) measurements of C4 solutions with varying cobalt dichloride concentrations to determine the corresponding relaxivities, r1 and r2. These relaxation parameters were investigated at different field strengths, temperatures and orientations. T1 measurements obtained at 1.5 T and 3.0 T, as well as at room and body temperature, showed that r1 is field-independent and temperature-independent. Conversely, the T2 values at 3.0 T were shorter than at 1.5 T, while the T2 values at body temperature were slightly higher than at room temperature. By examining the relaxivities with the C4 vials aligned in three different planes, we found no orientation-dependence. With these relaxation characteristics, we aim to develop pulse sequences that will enhance the C4 signal against prostatic stroma. Ultimately, the use of C4 as a positive contrast agent marker will encourage the use of MRI to obtain an accurate representation of the radiation dose delivered to the prostate and surrounding normal anatomical structures. PMID:24778352

  7. Altered Utilization of N-Acetyl-d-Galactosamine by Escherichia coli O157:H7 from the 2006 Spinach Outbreak▿

    PubMed Central

    Mukherjee, Amit; Mammel, Mark K.; LeClerc, J. Eugene; Cebula, Thomas A.

    2008-01-01

    In silico analyses of previously sequenced strains of Escherichia coli O157:H7, EDL933 and Sakai, localized the gene cluster for the utilization of N-acetyl-d-galactosamine (Aga) and d-galactosamine (Gam). This gene cluster encodes the Aga phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) and other catabolic enzymes responsible for transport and catabolism of Aga. As the complete coding sequences for enzyme IIA (EIIA)Aga/Gam, EIIBAga, EIICAga, and EIIDAga of the Aga PTS are present, E. coli O157:H7 strains normally are able to utilize Aga as a sole carbon source. The Gam PTS complex, in contrast, lacks EIICGam, and consequently, E. coli O157:H7 strains cannot utilize Gam. Phenotypic analyses of 120 independent isolates of E. coli O157:H7 from our culture collection revealed that the overwhelming majority (118/120) displayed the expected Aga+ Gam− phenotype. Yet, when 194 individual isolates, derived from a 2006 spinach-associated E. coli O157:H7 outbreak, were analyzed, all (194/194) displayed an Aga− Gam− phenotype. Comparison of aga/gam sequences from two spinach isolates with those of EDL933 and Sakai revealed a single nucleotide change (G:C→A:T) in the agaF gene in the spinach-associated isolates. The base substitution in agaF, which encodes EIIAAga/Gam of the PTS, changes a conserved glycine residue to serine (Gly91Ser). Pyrosequencing of this region showed that all spinach-associated E. coli O157:H7 isolates harbored this same G:C→A:T substitution. Notably, when agaF+ was cloned into an expression vector and transformed into six spinach isolates, all (6/6) were able to grow on Aga, thus demonstrating that the Gly91Ser substitution underlies the Aga− phenotype in these isolates. PMID:18156259

  8. N-acetyl-cysteine and prostaglandin. Comparable protection against experimental ethanol injury in the stomach independent of mucus thickness.

    PubMed

    Henagan, J M; Smith, G S; Schmidt, K L; Miller, T A

    1986-12-01

    The role of barrier mucus in mediating the protective effects of 16,16 dimethyl PGE2 (dm PGE2) against ethanol-induced gastric injury, with and without concomitant treatment with N-acetyl-cysteine (NAC), a potent mucolytic agent, was evaluated. Fasted rats were orally administered either saline, 10 micrograms/kg dm PGE2, 20% NAC, or 10 micrograms/kg dm PGE2 plus 20% NAC. In the first study, the rats were killed 15 minutes later and their stomachs were removed and assayed for barrier mucus adherent to the gastric wall using the Alcian blue technique. In the second study, the rats were orally given 2 mL of absolute ethanol (EtOH) after receiving one of these pretreatment regimens, and 5 minutes later they were killed and their stomachs were evaluated histologically by light microscopy for the magnitude of EtOH injury. Although NAC significantly reduced the thickness of barrier mucus by 76% when compared with control animals, it did not adversely affect the ability of dm PGE2 to spare the deep epithelium from injury by EtOH. In fact, NAC was as effective a protective agent as dm PGE2. Neither agent prevented damage to the surface epithelium by EtOH, verifying previous studies regarding the protective effects of prostaglandins. These results indicate that both dm PGE2 and NAC prevent EtOH-induced damage to the deeper layers of the gastric mucosa independent of mucus gel layer thickness, suggesting that other mechanisms than mucus are involved in mediating this protection.

  9. Rapid transport of muco-inert nanoparticles in cystic fibrosis sputum treated with N-acetyl cysteine

    PubMed Central

    Suk, Jung Soo; Lai, Samuel K; Boylan, Nicholas J; Dawson, Michelle R; Boyle, Michael P; Hanes, Justin

    2011-01-01

    Aims Sputum poses a critical diffusional barrier that strongly limits the efficacy of drug and gene carriers in the airways of individuals with cystic fibrosis (CF). Previous attempts to enhance particle penetration of CF sputum have focused on either reducing its barrier properties via mucolytics, or decreasing particle adhesion to sputum constituents by coating the particle surface with non-mucoadhesive polymers, including polyethylene glycol (PEG). Neither approach has enabled particles to penetrate expectorated sputum at rates previously observed for non-mucoadhesive nanoparticles in human cervicovaginal mucus. Here, we sought to investigate whether a common mucolytic, N-acetyl cysteine (NAC), in combination with dense PEG coatings on particles, can synergistically enhance particle penetration across fresh undiluted CF sputum. Materials & methods We used high-resolution multiple particle tracking to measure the diffusion of uncoated and PEG-coated nanoparticles in native and NAC-treated CF sputum. Results We discovered that 200 nm particles, if densely coated with PEG, were able to penetrate CF sputum pretreated with NAC with average speeds approaching their theoretical speeds in water. Based on the rapid penetration of PEG-coated particles in NAC-treated sputum, we determined that the average spacing between sputum mesh elements was increased from 145 ± 50 nm to 230 ± 50 nm upon NAC treatment. Mathematical models based on particle transport rates suggest as much as 75 and 30% of 200 and 500 nm PEG-coated particles, respectively, may penetrate a physiologically thick NAC-treated CF sputum layer within 20 min. Uncoated particles were trapped in CF sputum pretreated with NAC nearly to the same extent as in native sputum, suggesting that NAC treatment alone offered little improvement to particle penetration. Conclusion NAC facilitated rapid diffusion of PEG-coated, muco-inert nanoparticles in CF sputum. Our results provide a promising strategy to improve drug

  10. MRI characterization of cobalt dichloride-N-acetyl cysteine (C4) contrast agent marker for prostate brachytherapy

    NASA Astrophysics Data System (ADS)

    Lim, Tze Yee; Stafford, R. Jason; Kudchadker, Rajat J.; Sankaranarayanapillai, Madhuri; Ibbott, Geoffrey; Rao, Arvind; Martirosyan, Karen S.; Frank, Steven J.

    2014-05-01

    Brachytherapy, a radiotherapy technique for treating prostate cancer, involves the implantation of numerous radioactive seeds into the prostate. While the implanted seeds can be easily identified on a computed tomography image, distinguishing the prostate and surrounding soft tissues is not as straightforward. Magnetic resonance imaging (MRI) offers superior anatomical delineation, but the seeds appear as dark voids and are difficult to identify, thus creating a conundrum. Cobalt dichloride-N-acetyl-cysteine (C4) has previously been shown to be promising as an encapsulated contrast agent marker. We performed spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) measurements of C4 solutions with varying cobalt dichloride concentrations to determine the corresponding relaxivities, r1 and r2. These relaxation parameters were investigated at different field strengths, temperatures and orientations. T1 measurements obtained at 1.5 and 3.0 T, as well as at room and body temperature, showed that r1 is field-independent and temperature-independent. Conversely, the T2 values at 3.0 T were shorter than at 1.5 T, while the T2 values at body temperature were slightly higher than at room temperature. By examining the relaxivities with the C4 vials aligned in three different planes, we found no orientation-dependence. With these relaxation characteristics, we aim to develop pulse sequences that will enhance the C4 signal against prostatic stroma. Ultimately, the use of C4 as a positive contrast agent marker will encourage the use of MRI to obtain an accurate representation of the radiation dose delivered to the prostate and surrounding normal anatomical structures.

  11. N-acetyl-cysteine and prostaglandin. Comparable protection against experimental ethanol injury in the stomach independent of mucus thickness.

    PubMed Central

    Henagan, J M; Smith, G S; Schmidt, K L; Miller, T A

    1986-01-01

    The role of barrier mucus in mediating the protective effects of 16,16 dimethyl PGE2 (dm PGE2) against ethanol-induced gastric injury, with and without concomitant treatment with N-acetyl-cysteine (NAC), a potent mucolytic agent, was evaluated. Fasted rats were orally administered either saline, 10 micrograms/kg dm PGE2, 20% NAC, or 10 micrograms/kg dm PGE2 plus 20% NAC. In the first study, the rats were killed 15 minutes later and their stomachs were removed and assayed for barrier mucus adherent to the gastric wall using the Alcian blue technique. In the second study, the rats were orally given 2 mL of absolute ethanol (EtOH) after receiving one of these pretreatment regimens, and 5 minutes later they were killed and their stomachs were evaluated histologically by light microscopy for the magnitude of EtOH injury. Although NAC significantly reduced the thickness of barrier mucus by 76% when compared with control animals, it did not adversely affect the ability of dm PGE2 to spare the deep epithelium from injury by EtOH. In fact, NAC was as effective a protective agent as dm PGE2. Neither agent prevented damage to the surface epithelium by EtOH, verifying previous studies regarding the protective effects of prostaglandins. These results indicate that both dm PGE2 and NAC prevent EtOH-induced damage to the deeper layers of the gastric mucosa independent of mucus gel layer thickness, suggesting that other mechanisms than mucus are involved in mediating this protection. Images FIG. 3. FIG. 4. FIG. 5. FIG. 6. PMID:3789839

  12. Rapid transport of muco-inert nanoparticles in cystic fibrosis sputum treated with N-acetyl cysteine.

    PubMed

    Suk, Jung Soo; Lai, Samuel K; Boylan, Nicholas J; Dawson, Michelle R; Boyle, Michael P; Hanes, Justin

    2011-02-01

    Sputum poses a critical diffusional barrier that strongly limits the efficacy of drug and gene carriers in the airways of individuals with cystic fibrosis (CF). Previous attempts to enhance particle penetration of CF sputum have focused on either reducing its barrier properties via mucolytics, or decreasing particle adhesion to sputum constituents by coating the particle surface with non-mucoadhesive polymers, including polyethylene glycol (PEG). Neither approach has enabled particles to penetrate expectorated sputum at rates previously observed for non-mucoadhesive nanoparticles in human cervicovaginal mucus. Here, we sought to investigate whether a common mucolytic, N-acetyl cysteine (NAC), in combination with dense PEG coatings on particles, can synergistically enhance particle penetration across fresh undiluted CF sputum. We used high-resolution multiple particle tracking to measure the diffusion of uncoated and PEG-coated nanoparticles in native and NAC-treated CF sputum. We discovered that 200 nm particles, if densely coated with PEG, were able to penetrate CF sputum pretreated with NAC with average speeds approaching their theoretical speeds in water. Based on the rapid penetration of PEG-coated particles in NAC-treated sputum, we determined that the average spacing between sputum mesh elements was increased from 145 ± 50 nm to 230 ± 50 nm upon NAC treatment. Mathematical models based on particle transport rates suggest as much as 75 and 30% of 200 and 500 nm PEG-coated particles, respectively, may penetrate a physiologically thick NAC-treated CF sputum layer within 20 min. Uncoated particles were trapped in CF sputum pretreated with NAC nearly to the same extent as in native sputum, suggesting that NAC treatment alone offered little improvement to particle penetration. NAC facilitated rapid diffusion of PEG-coated, muco-inert nanoparticles in CF sputum. Our results provide a promising strategy to improve drug and gene carrier penetration in CF sputum

  13. N-acetyl-beta-D-glucosaminidase index as an early biomarker for chronic kidney disease in cats with hyperthyroidism.

    PubMed

    Lapointe, C; Bélanger, M-C; Dunn, M; Moreau, M; Bédard, C

    2008-01-01

    Hyperthyroid cats are at risk of developing azotemic chronic kidney disease (CKD) and diagnostic tools currently used to screen for CKD in hyperthyroid cats are either unreliable or impractical. Urine N-acetyl-beta-D-glucosaminidase index (NAG(i)) is a good biomarker for azotemic CKD in hyperthyroid cats. Twenty-four newly diagnosed nonazotemic hyperthyroid cats and 10 healthy cats. All cats were evaluated for hyperthyroidism at baseline. Hyperthyroid cats were treated with methimazole and reevaluated once euthyroid. At the end of the study, cats were divided into 3 groups: healthy cats, nonazotemic, and azotemic euthyroid cats. Baseline group characteristics were compared to predict azotemic CKD. The influence of treatment on NAG(i) was evaluated. Baseline NAG(i) was significantly different among groups (P= .004). Azotemic cats had a higher median value (13.12 U/g) when compared with healthy cats (1.38 U/g). With NAG(i) >2.76 U/g, negative and positive predictive values for development of azotemia were 77.7 and 50%, whereas the combination of a urine specific gravity (USG) 7.80 microg/dL enhanced predictive values to 88.9 and 83.3%, respectively. NAG(i) values decreased significantly over time in treated nonazotemic cats. Baseline NAG(i) did not differentiate azotemic from nonazotemic euthyroid cats. NAG(i) could be used to assess renal function during medical therapy allowing the clinician to adjust methimazole dosage accordingly. The combination of USG and T(4) could optimize identification of appropriate candidates for permanent treatment of hyperthyroidism.

  14. Mechanism for N-acetyl-2-aminofluorene-induced frameshift mutagenesis by Escherichia coli DNA polymerase I (Klenow fragment).

    PubMed

    Gill, Joshua P; Romano, Louis J

    2005-11-22

    N-Acetyl-2-aminofluorene (AAF) is a chemical carcinogen that reacts with guanines at the C8 position in DNA to form a structure that interferes with DNA replication. In bacteria, the NarI restriction enzyme recognition sequence (G1G2CG3CC) is a very strong mutational hot spot when an AAF adduct is positioned at G3 of this sequence, causing predominantly a -2 frameshift GC dinucleotide deletion mutation. In this study, templates were constructed that contained an AAF adduct at this position, and primers of different lengths were prepared such that the primer ended one nucleotide before or opposite or one nucleotide after the adduct site. Primer extension and gel shift binding assays were used to study the mechanism of bypass by the Escherichia coli DNA polymerase I (Klenow fragment) in the presence of these templates. Primer extension in the presence of all four dNTPs produced a fully extended product using the unmodified template, while with the AAF-modified template synthesis initially stalled at the adduct site and subsequent synthesis resulted in a product that contained the GC dinucleotide deletion. Extension product and gel shift binding analyses were consistent with the formation of a two-nucleotide bulge structure upstream of the active site of the polymerase after a nucleotide is incorporated across from the adduct. These data support a model in which the AAF adduct in the NarI sequence specifically induces a structure upstream of the polymerase active site that leads to the GC frameshift mutation and that it is this structure that allows synthesis past the adduct to occur.

  15. Infrared-induced conformational isomerization and vibrational relaxation dynamics in melatonin and 5-methoxy-N-acetyl tryptophan methyl amide

    NASA Astrophysics Data System (ADS)

    Dian, Brian C.; Florio, Gina M.; Clarkson, Jasper R.; Longarte, Asier; Zwier, Timothy S.

    2004-05-01

    are compared with those for N-acetyl tryptophan methyl amide.

  16. Structural basis for substrate specificity and mechanism of N-acetyl-D-neuraminic acid lyase from Pasteurella multocida#

    PubMed Central

    Huynh, Nhung; Aye, Aye; Li, Yanhong; Yu, Hai; Cao, Hongzhi; Tiwari, Vinod Kumar; Shin, Don-Wook; Chen, Xi; Fisher, Andrew J.

    2013-01-01

    N -Acetylneuraminate lyases (NALs) or sialic acid aldolases catalyze the reversible aldol cleavage of N-acetylneuraminic acid (Neu5Ac, the most common form of sialic acid) to form pyruvate and N-acetyl-D-mannosamine (ManNAc). Although equilibrium favors sialic acid cleavage, these enzymes can be used for high-yield chemoenzymatic synthesis of structurally diverse sialic acids in the presence of excess pyruvate. Engineering these enzymes to synthesize structurally modified natural sialic acids and their non-natural derivatives holds promise in creating novel therapeutic agents. Atomic resolution structures of these enzymes will greatly assist in guiding mutagenic and modeling studies to engineer enzymes with altered substrate specificity. We report here the crystal structures of wild-type Pasteurella multocida N-acetylneuraminate lyase and its K164A mutant. Like other bacterial lyases, it assembles into a homotetramer with each monomer folding into a classic (β/α)8 TIM barrel. Two wild-type structures were determined; in the absence of substrates, and trapped in a Schiff base intermediate between Lys164 and pyruvate, respectively. Three structures of the K164A variant were determined: one in the absence of substrates and two binary complexes with N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), respectively. Both sialic acids bind to the active site in the open-chain ketone form of the monosaccharide. The structures reveal that every hydroxyl group of the linear sugars makes hydrogen bond interactions with the enzyme and the residues that determine specificity were identified. Additionally, the structures lend some clues in explaining the natural discrimination of sialic acid substrates between the P. multocida and E. coli NALs. PMID:24152047

  17. Recovery of active N-acetyl-D-glucosamine 2-epimerase from inclusion bodies by solubilization with non-denaturing buffers.

    PubMed

    Lu, Shih-Chin; Lin, Sung-Chyr

    2012-01-05

    Overexpression of recombinant N-acetyl-D-glucosamine 2-epimerase, one of the key enzymes for the synthesis of N-acetylneuraminic acid, in E. coli led to the formation of protein inclusion bodies. In this study we report the recovery of active epimerase from inclusion bodies by direct solubilization with Tris buffer. At pH 7.0, 25% of the inclusion bodies were solubilized with Tris buffer. The specific activity of the solubilized proteins, 2.08±0.02 U/mg, was similar to that of the native protein, 2.13±0.01 U/mg. The result of circular dichroism spectroscopy analysis indicated that the structure of the solubilized epimerase obtained with pH 7.0 Tris buffer was similar to that of the native epimerase purified from the clarified cell lysate. As expected, the extent of deviation in CD spectra increased with buffer pH. The total enzyme activity recovered by solubilization from inclusion bodies, 170.41±10.06 U/l, was more than 2.5 times higher than that from the clarified cell lysate, 67.32±5.53 U/l. The results reported in this study confirm the hypothesis that the aggregation of proteins into inclusion bodies is reversible and suggest that direct solubilization with non-denaturing buffers is a promising approach for the recovery of active proteins from inclusion bodies, especially for aggregation-prone multisubunit proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Reactive oxygen species scavenger N-acetyl cysteine reduces methamphetamine-induced hyperthermia without affecting motor activity in mice

    PubMed Central

    Sanchez-Alavez, Manuel; Bortell, Nikki; Galmozzi, Andrea; Conti, Bruno; Marcondes, Maria Cecilia G.

    2014-01-01

    Hyperthermia is a potentially lethal side effect of Methamphetamine (Meth) abuse, which involves the participation of peripheral thermogenic sites such as the Brown Adipose Tissue (BAT). In a previous study we found that the anti-oxidant N-acetyl cysteine (NAC) can prevent the high increase in temperature in a mouse model of Meth-hyperthermia. Here, we have further explored the ability of NAC to modulate Meth-induced hyperthermia in correlation with changes in BAT. We found that NAC treatment in controls causes hypothermia, and, when administered prior or upon the onset of Meth-induced hyperthermia, can ameliorate the temperature increase and preserve mitochondrial numbers and integrity, without affecting locomotor activity. This was different from Dantrolene, which decreased motor activity without affecting temperature. The effects of NAC were seen in spite of its inability to recover the decrease of mitochondrial superoxide induced in BAT by Meth. In addition, NAC did not prevent the Meth-induced decrease of BAT glutathione. Treatment with S-adenosyl-L-methionine, which improves glutathione activity, had an effect in ameliorating Meth-induced hyperthermia, but also modulated motor activity. This suggests a role for the remaining glutathione for controlling temperature. However, the mechanism by which NAC operates is independent of glutathione levels in BAT and specific to temperature. Our results show that, in spite of the absence of a clear mechanism of action, NAC is a pharmacological tool to examine the dissociation between Meth-induced hyperthermia and motor activity, and a drug of potential utility in treating the hyperthermia associated with Meth-abuse. PMID:26346736

  19. Tissue damage in rat ovaries subjected to torsion and detorsion: effects of L-carnitine and N-acetyl cysteine.

    PubMed

    Usta, Ufuk; Inan, Mustafa; Erbas, Hakan; Aydogdu, Nurettin; Oz Puyan, Fulya; Altaner, Semsi

    2008-05-01

    We aimed to evaluate histopathological changes, to detect HIF-1alpha staining intensities and to determine MDA levels in rat ovaries, which were subjected to torsion and detorsion and treated with L -carnitine or N-acetyl cysteine (NAC). Forty-eight prepubertal female Sprague-Dawley rats were divided into five groups (n = 8): 1, control; 2, ischemia; 3, reperfusion; 4, L -carnitine; and 5, NAC groups. In groups 3, 4 and 5, an ischemic period of 3 h was followed by reperfusion for 24 h. In groups 4 and 5, ischemia was performed and either L -carnitine or NAC was infused intraperitoneally 30 min before reperfusion. Ovarian tissues were examined histopathologically; tissue MDA levels and serum IL-6 levels were determined biochemically. HIF-1alpha was applied to all ovaries immunohistochemically. Total tissue damage scores, tissue MDA levels and HIF-1alpha scores, were significantly higher in group 2 (all P < 0.001) than group 4, and group 3 than group 4 (P < 0.001, P = 0.05 and P < 0.001, respectively). They were also significantly higher in group 2 (all P < 0.001) than group 5. When group 3 is compared to group 5, total tissue damage scores and tissue MDA levels were significantly higher in the former (P < 0.01 and P < 0.001, respectively). Serum IL-6 levels were significantly higher in group 2 when compared to groups 1, 4 and 5 (all P < 0.01). The degree of tissue damage of the torsioned ovaries decreased after a reperfusion period of 24 h in the torsioned ovaries. However, ovaries of both L -carnitine and NAC groups showed better recovery than the reperfusion group.

  20. N-Acetyl-L-cysteine protects thyroid cells against DNA damage induced by external and internal irradiation.

    PubMed

    Kurashige, Tomomi; Shimamura, Mika; Nagayama, Yuji

    2017-09-04

    We evaluated the effect of the antioxidant N-acetyl-L-cysteine (NAC) on the levels of reactive oxygen species (ROS), DNA double strand breaks (DSB) and micronuclei (MN) induced by internal and external irradiation using a rat thyroid cell line PCCL3. In internal irradiation experiments, ROS and DSB levels increased immediately after (131)I addition and then gradually declined, resulting in very high levels of MN at 24 and 48 h. NAC administration both pre- and also post-(131)I addition suppressed ROS, DSB and MN. In external irradiation experiments with a low dose (0.5 Gy), ROS and DSB increased shortly and could be prevented by NAC administration pre-, but not post-irradiation. In contrast, external irradiation with a high dose (5 Gy) increased ROS and DSB in a bimodal way: ROS and DSB levels increased immediately after irradiation, quickly returned to the basal levels and gradually rose again after >24 h. The second phase was in parallel with an increase in 4-hydroxy-2-nonenal. The number of MN induced by the second wave of ROS/DSB elevations was much higher than that by the first peak. In this situation, NAC administered pre- and post-irradiation comparably suppressed MN induced by a delayed ROS elevation. In conclusion, a prolonged ROS increase during internal irradiation and a delayed ROS increase after external irradiation with a high dose caused serious DNA damage, which were efficiently prevented by NAC. Thus, NAC administration even both after internal or external irradiation prevents ROS increase and eventual DNA damage.

  1. Surface modifications in the platelets of a patient with alpha-N-acetyl-D-galactosamine residues, the Tn-syndrome.

    PubMed Central

    Nurden, A T; Dupuis, D; Pidard, D; Kieffer, N; Kunicki, T J; Cartron, J P

    1982-01-01

    The Tn-syndrome is an acquired disorder characterized by the polyagglutination of blood cells and the pathological exposure of alpha-N-acetyl-D-galactosamine residues (Tn-antigen) at the cell surface. We now report studies on the platelet of a patient (Ba.) of which 81% reacted positively with a fluorescein conjugate of Helix pomatia agglutinin (HPA). The surface proteins of Ba. platelets were labeled with 125I by the lactoperoxidase-catalyzed procedure; single and two-dimensional electrophoresis on sodium dodecyl sulfate (SDS)-polyacrylamide gels was followed by autoradiography that revealed normal 125I-labeling of the major membrane glycoproteins (GP) but that GP Ib had a faster than normal migration. the abnormal GP Ib of Ba. platelets was strongly labeled when platelet suspensions were treated sequentially with neuraminidase, galactose oxidase, and sodium [3H]borohydride. Unlike the GP Ib of normal human platelets, it was also strongly labeled when Ba. platelets were treated with galactose oxidase and sodium [3H]borohydride alone. Both the alloantigen, PlA1, and quinidine-dependent antibody receptor activity were normally expressed by Ba. platelets, which also bound a monoclonal antibody (AN51) to GP Ib. Analysis of Ba. platelets by crossed immunoelectrophoresis using a rabbit anti-human platelet antibody preparation revealed the presence of an immunoprecipitate in the GP Ib position that had an abnormal appearance and migration in the second dimension. An altered position of the precipitate given by Factor VIIIR:Ag was also noted. Incorporation of HPA into the agarose gel during the first dimension electrophoresis resulted in the specific precipitation of the abnormal GP Ib of Ba. platelets. Our studies show that circulating Tn-platelets contain GP Ib with a modified oligosaccharide chain structure responsible for the platelet expression of Tn-antigen activity. Images PMID:7174794

  2. Differential effects of N-acetyl-aspartyl-glutamate on synaptic and extrasynaptic NMDA receptors are subunit- and pH-dependent in the CA1 region of the mouse hippocampus.

    PubMed

    Khacho, Pamela; Wang, Boyang; Ahlskog, Nina; Hristova, Elitza; Bergeron, Richard

    2015-10-01

    Ischemic strokes cause excessive release of glutamate, leading to overactivation of N-methyl-d-aspartate receptors (NMDARs) and excitotoxicity-induced neuronal death. For this reason, inhibition of NMDARs has been a central focus in identifying mechanisms to avert this extensive neuronal damage. N-acetyl-aspartyl-glutamate (NAAG), the most abundant neuropeptide in the brain, is neuroprotective in ischemic conditions in vivo. Despite this evidence, the exact mechanism underlying its neuroprotection, and more specifically its effect on NMDARs, is currently unknown due to conflicting results in the literature. Here, we uncover a pH-dependent subunit-specific action of NAAG on NMDARs. Using whole-cell electrophysiological recordings on acute hippocampal slices from adult mice and on HEK293 cells, we found that NAAG increases synaptic GluN2A-containing NMDAR EPSCs, while effectively decreasing extrasynaptic GluN2B-containing NMDAR EPSCs in physiological pH. Intriguingly, the results of our study further show that in low pH, which is a physiological occurrence during ischemia, NAAG depresses GluN2A-containing NMDAR EPSCs and amplifies its inhibitory effect on GluN2B-containing NMDAR EPSCs, as well as upregulates the surface expression of the GluN2A subunit. Altogether, our data demonstrate that NAAG has differential effects on NMDAR function based on subunit composition and pH. These findings suggest that the role of NAAG as a neuroprotective agent during an ischemic stroke is likely mediated by its ability to reduce NMDAR excitation. The inhibitory effect of NAAG on NMDARs and its enhanced function in acidic conditions make NAAG a prime therapeutic agent for the treatment of ischemic events.

  3. The effect of substitution of the N-acetyl groups of N-acetylgalactosamine residues in chondroitin sulfate on its degradation by chondroitinase ABC.

    PubMed

    Madhunapantula, Subbarao V; Achur, Rajeshwara N; Bhavanandan, Veer P; Gowda, D Channe

    2007-11-01

    Chondroitinase ABC is a lyase that degrades chondroitin sulfate, dermatan sulfate and hyaluronic acid into disaccharides. The purpose of this study was to determine the ability of chondroitinase ABC to degrade chondroitin sulfate in which the N-acetyl groups are substituted with different acyl groups. The bovine tracheal chondroitin sulfate A (bCSA) was N-deacetylated by hydrazinolysis, and the free amino groups derivatized into N-formyl, N-propionyl, N-butyryl, N-hexanoyl or N-benzoyl amides. Treatment of the N-acyl or N-benzoyl derivatives of bCSA with chondroitinase ABC and analysis of the products showed that the N-formyl, N-hexanoyl and N-benzoyl derivatives are completely resistant to the enzyme. In contrast, the N-propionyl or N-butyryl derivatives were degraded into disaccharides with slower kinetics compared to that of unmodified bCSA. The rate of degradation of bCSA derivatives by the enzyme was found to be in the order of N-acetyl>N-propionyl>N-butyryl bCSA. These results have important implications for understanding the interaction of N-acetyl groups of glycosaminoglycans with chondroitinase ABC.

  4. Synthesis and characterization of N-parinaroyl analogs of ganglioside GM3 and de-N-acetyl GM3. Interactions with the EGF receptor kinase

    NASA Technical Reports Server (NTRS)

    Song, W.; Welti, R.; Hafner-Strauss, S.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    A specific plasma membrane glycosphingolipid, known as ganglioside GM3, can regulate the intrinsic tyrosyl kinase activity of the epidermal growth factor (EGF) receptor; this modulation is not associated with alterations in hormone binding to the receptor. GM3 inhibits EGF receptor tyrosyl kinase activity in detergent micelles, in plasma membrane vesicles, and in whole cells. In addition, immunoaffinity-purified EGF receptor preparations contain ganglioside GM3 (Hanai et al. (1988) J. Biol. Chem. 263, 10915-10921), implying that the glycosphingolipid is intimately associated with the receptor kinase in cell membranes. Both the nature of this association and the molecular mechanism of kinase inhibition remain to be elucidated. In this report, we describe the synthesis of a fluorescent analog of ganglioside GM3, in which the native fatty acid was replaced with trans-parinaric acid. This glycosphingolipid inhibited the receptor kinase activity in a manner similar to that of the native ganglioside. A modified fluorescent glycosphingolipid, N-trans-parinaroyl de-N-acetyl ganglioside GM3, was also prepared. This analog, like the nonfluorescent de-N-acetyl ganglioside GM3, had no effect on receptor kinase activity. Results from tryptophan fluorescence quenching and steady-state anisotropy measurements in membranes containing these fluorescent probes and the human EGF receptor were consistent with the notion that GM3, but not de-N-acetyl GM3, interacts specifically with the receptor in intact membranes.

  5. Synthesis and characterization of N-parinaroyl analogs of ganglioside GM3 and de-N-acetyl GM3. Interactions with the EGF receptor kinase

    NASA Technical Reports Server (NTRS)

    Song, W.; Welti, R.; Hafner-Strauss, S.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    A specific plasma membrane glycosphingolipid, known as ganglioside GM3, can regulate the intrinsic tyrosyl kinase activity of the epidermal growth factor (EGF) receptor; this modulation is not associated with alterations in hormone binding to the receptor. GM3 inhibits EGF receptor tyrosyl kinase activity in detergent micelles, in plasma membrane vesicles, and in whole cells. In addition, immunoaffinity-purified EGF receptor preparations contain ganglioside GM3 (Hanai et al. (1988) J. Biol. Chem. 263, 10915-10921), implying that the glycosphingolipid is intimately associated with the receptor kinase in cell membranes. Both the nature of this association and the molecular mechanism of kinase inhibition remain to be elucidated. In this report, we describe the synthesis of a fluorescent analog of ganglioside GM3, in which the native fatty acid was replaced with trans-parinaric acid. This glycosphingolipid inhibited the receptor kinase activity in a manner similar to that of the native ganglioside. A modified fluorescent glycosphingolipid, N-trans-parinaroyl de-N-acetyl ganglioside GM3, was also prepared. This analog, like the nonfluorescent de-N-acetyl ganglioside GM3, had no effect on receptor kinase activity. Results from tryptophan fluorescence quenching and steady-state anisotropy measurements in membranes containing these fluorescent probes and the human EGF receptor were consistent with the notion that GM3, but not de-N-acetyl GM3, interacts specifically with the receptor in intact membranes.

  6. Evaluation of efficacy of vitamin E and N-acetyl cysteine in gentamicin-induced nephrotoxicity in rats.

    PubMed

    Patel Manali, Bhalchandra; Deshpande, Shrikalp; Shah, Gaurang

    2011-01-01

    Gentamicin (GM), an aminoglycoside, is widely employed in clinical practice for the treatment of serious gram-negative infections. The clinical utility of GM is limited by the frequent incidence of acute renal failure. This study was designed to investigate treatment and posttreatment renoprotective potential of vitamin E and N-acetyl cysteine (NAC) against GM-induced oxidative stress and renal dysfunction. Male Sprague-Dawley rats were divided into six groups: first group is the control group that received olive oil (0.1 mL/100 g B.W.), second is the one that was treated with GM (80 mg/kg/i.p./8 days), third is the one that was treated with GM (80 mg/kg/i.p./8 days) and vitamin E (50 mg/kg/i.p./8 days), fourth is the one that was treated with GM (80 mg/kg/i.p./8 days) and NAC (50 mg/kg/i.p./8 days), fifth is the one that was treated with GM (80 mg/kg/i.p./8 days), vitamin E (50 mg/kg/i.p./8 days), and NAC (50 mg/kg/i.p./8 days), and sixth is the one that was treated with GM initially for 8 days (at 80 mg/kg/i.p.) after which vitamin E (at 50 mg/kg/i.p.) and NAC (at 50 mg/kg/i.p.) were administered for 8 days. Serum creatinine, blood urea nitrogen, serum glucose, renal malondialdehyde, renal reduced glutathione, urine sodium, fractional excretion of sodium, and histopathological examination of kidney were performed after treatment. Gentamicin treatment caused nephrotoxicity as evidenced by marked elevation in serum creatinine, blood urea nitrogen, renal malondialdehyde, urine sodium, and fractional excretion of sodium. Study of renal morphology showed marked loss of epithelium in proximal convoluted tubule, inflammatory infiltrate in the form of lymphocytes, mainly in interstitium. Treatment and posttreatment with vitamin E and NAC significantly restored renal functions, reduced lipid peroxidation, enhanced reduced glutathione level, and restored the biochemical parameters. The results of this study demonstrate the therapeutic potential of vitamin E and NAC in

  7. N-Acetyl-cysteine causes analgesia by reinforcing the endogenous activation of type-2 metabotropic glutamate receptors

    PubMed Central

    2012-01-01

    Background Pharmacological activation of type-2 metabotropic glutamate receptors (mGlu2 receptors) causes analgesia in experimental models of inflammatory and neuropathic pain. Presynaptic mGlu2 receptors are activated by the glutamate released from astrocytes by means of the cystine/glutamate antiporter (System xc- or Sxc-). We examined the analgesic activity of the Sxc- activator, N-acetyl-cysteine (NAC), in mice developing inflammatory or neuropathic pain. Results A single injection of NAC (100 mg/kg, i.p.) reduced nocifensive behavior in the second phase of the formalin test. NAC-induced analgesia was abrogated by the Sxc- inhibitor, sulphasalazine (8 mg/kg, i.p.) or by the mGlu2/3 receptor antagonist, LY341495 (1 mg/kg, i.p.). NAC still caused analgesia in mGlu3−/− mice, but was inactive in mGlu2−/− mice. In wild-type mice, NAC retained the analgesic activity in the formalin test when injected daily for 7 days, indicating the lack of tolerance. Both single and repeated injections of NAC also caused analgesia in the complete Freund’s adjuvant (CFA) model of chronic inflammatory pain, and, again, analgesia was abolished by LY341495. Data obtained in mice developing neuropathic pain in response to chronic constriction injury (CCI) of the sciatic nerve were divergent. In this model, a single injection of NAC caused analgesia that was reversed by LY341495, whereas repeated injections of NAC were ineffective. Thus, tolerance to NAC-induced analgesia developed in the CCI model, but not in models of inflammatory pain. The CFA and CCI models differed with respect to the expression levels of xCT (the catalytic subunit of Sxc-) and activator of G-protein signaling type-3 (AGS3) in the dorsal portion of the lumbar spinal cord. CFA-treated mice showed no change in either protein, whereas CCI mice showed an ipislateral reduction in xCT levels and a bilateral increase in AGS3 levels in the spinal cord. Conclusions These data demonstrate that pharmacological

  8. Air pollution and urinary n-acetyl-B-glucosaminidase levels in residents living near a cement plant.

    PubMed

    Jung, Min Soo; Kim, Jae Yoon; Lee, Hyun Seung; Lee, Chul Gab; Song, Han Soo

    2016-01-01

    To identify adverse renal effects due to air pollution derived from a cement plant in Korea. Urinary n-acetyl-B-glucosaminidase (U-NAG) levels in residents living near a cement plant were compared to those in a group who lived farther away from the plant. From June to August 2013 and from August to November 2014, laboratory tests for U-NAG and heavy metal were conducted on 547 study participants. Based on the level of air pollution exposure, subjects were divided into the "less exposed group," (LEG) which consisted of 66 persons who lived more than 5 km away from the cement plant, the "more exposed group from the rural area" (MEG-R), which consisted of 272 persons, and the "more exposed group from downtown area" (MEG-D), which consisted of 209 persons who lived within a 1 km radius of the cement plant. U-NAG levels >5.67 U/L were defined as "higher U-NAG" levels. We compared the prevalence of higher U-NAG levels and estimated the adjusted odds ratio (OR) by air pollution exposure using a chi-square test and multiple logistic regression analysis. Further, we estimated the interaction between air pollution exposure and heavy metal exposure in renal toxicity. The OR of higher U-NAG levels by MEG-D and MEG-R compared to LEG was 2.13 (95 % CI 0.86-4.96) and 4.79 (95 CI 1.65-10.01), respectively. Urinary cadmium (U-Cd), urinary mercury (U-Hg), age, occupation, hypertension, and diabetes had a significant association with higher U-NAG levels. However, blood lead (B-Pb), sex, and smoking were not associated with higher U-NAG. Especially, concurrent exposure to heavy metals (U-Hg or/and U-Cd) and air pollution had an additive adverse effect. In the group with both 4(th) quartile heavy metal exposure (U-Cd or/and U-Hg) and air pollution exposure, the OR in MEG-R and MEG-D was 6.49 (95 % 1.42-29.65) and 8.12 (95 % CI 1.74-37.92), respectively, after adjustment for age, occupation, hypertension, diabetes. U-NAG levels seem to be affected by air pollution exposure as well

  9. Renal protective effect of N-acetyl-seryl-aspartyl-lysyl-proline in dahl salt-sensitive rats.

    PubMed

    Worou, Morel E; Liao, Tang-Dong; D'Ambrosio, Martin; Nakagawa, Pablo; Janic, Branislava; Peterson, Edward L; Rhaleb, Nour-Eddine; Carretero, Oscar A

    2015-10-01

    N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a natural tetrapeptide with anti-inflammatory and antifibrotic properties. Its effect on salt-sensitive (SS) hypertension is unknown. We hypothesized that in Dahl SS rats on high-salt (HS) diet, Ac-SDKP prevents loss of nephrin expression and renal immune cell infiltration, leading to a decrease in albuminuria, renal inflammation, fibrosis, and glomerulosclerosis. To test this, Dahl SS rats and consomic SS13BN controls were fed either a low-salt (0.23% NaCl) or HS (4% NaCl) diet and treated for 6 weeks with vehicle or Ac-SDKP at either low or high dose (800 or 1600 μg/kg per day, respectively). HS increased systolic blood pressure in SS rats (HS+vehicle, 186±5 versus low salt+vehicle, 141±3 mm Hg; P<0.005) but not in SS13BN rats. Ac-SDKP did not affect blood pressure. Compared with low salt, HS-induced albuminuria, renal inflammation, fibrosis, and glomerulosclerosis in both strains, but the damages were higher in SS than in SS13BN. Interestingly, in SS13BN rats, Ac-SDKP prevented albuminuria induced by HS (HS+vehicle, 44±8 versus HS+low Ac-SDKP, 24±3 or HS+high Ac-SDKP, 8±1 mg/24 h; P<0.05), whereas in SS rats, only high Ac-SDKP dose significantly attenuated albuminuria (HS+vehicle, 94±10 versus HS+high Ac-SDKP, 57±7 mg/24 h; P<0.05). In both strains, Ac-SDKP prevented HS-induced inflammation, interstitial fibrosis, and glomerulosclerosis. In summary, in SS rats on HS diet, at low and high doses, Ac-SDKP prevented renal damage without affecting the blood pressure. Only the high dose of Ac-SDKP attenuated HS-induced albuminuria. Conversely, in SS13BN rats, both doses of Ac-SDKP prevented HS-induced renal damage and albuminuria.

  10. A GC/MS method for the quantitation of N-nitrosoproline and N-acetyl-S-allylcysteine in human urine

    PubMed Central

    Cope, Keary; Seifried, Harold; Seifried, Rebecca; Milner, John; Kris-Etherton, Penny; Harrison, Earl H.

    2009-01-01

    Biomarkers in urine can provide useful information about the bioactivation of chemical carcinogens and can be used to investigate the chemoprotective properties of dietary nutrients. N-nitrosoproline (NPRO) excretion has been used as an index for endogenous nitrosation. In vitro and animal studies have reported that compounds in garlic may suppress nitrosation and inhibit carcinogenesis. We present a new method for extraction and sensitive detection of both NPRO and N-acetyl-S-allylcysteine from urine. The latter is a major metabolite of S-allyl cysteine which is abundant in garlic. Urine was acidified and the organic acids extracted by reversed phase extraction (RP-SPE) and use of a polymeric weak anion exchange (WAX-SPE) resin. NPRO was quantified by isotope dilution gas chromatography-mass spectrometry using 13C5NPRO and N-nitrosopipecolic acid (NPIC) as internal standards. This method was used to analyze urine samples from a study that was designed to test whether garlic supplementation inhibits NPRO synthesis. Using this method, 2.4 to 46 ng of NPRO per mL urine was detected. The method is straightforward, reliable and can be performed with readily available GC/MS instruments. N-acetyl-S-allylcysteine was quantified in the same fraction and detectable at levels of 4.1 to 176.4 ng per mL of urine. The results suggest that 3 to 5 grams of garlic supplements inhibited NPRO synthesis to an extent similar to a 0.5 g dose of ascorbic acid or a commercial supplement of aged garlic extract. Urinary NPRO concentration was inversely associated with the N-acetyl-S-allylcysteine concentration. It is possible that allyl sulfur compounds found in garlic may inhibit nitrosation in humans. . PMID:19643074

  11. Aloe-emodin inhibited N-acetylation and DNA adduct of 2-aminofluorene and arylamine N-acetyltransferase gene expression in mouse leukemia L 1210 cells.

    PubMed

    Chung, Jing-Gung; Li, Yu-Ching; Lee, Yi-Min; Lin, Jing-Pin; Cheng, Kwork-Chui; Chang, Weng-Cheng

    2003-09-01

    N-Acetyltransferases (NATs) plays an important role in the first step of arylamine compounds metabolism. Polymorphic NAT is coded for rapid or slow acetylatoion phenotypes, which are recognized to affect cancer risk related to environmental exposure. Aloe-emodin has been shown to exit anticancer activity. The purpose of this study is to examine whether or not aloe-emodin could affect arylamine N-acetyltransferase (NAT) activity and gene expression (NAT mRNA) and DNA-2-aminofluorene (DNA-AF) adduct formation in mouse leukemia cells (L 1210). By using high performance liquid chromatography, N-acetylation and non-N-acetylation of AF were determined and quantitated. By using reverse transcriptase-polymerase chain reaction (RT-PCR) and PCR, NAT mRNA was determined and quantitated. Aloe-emodin displayed a dose-dependent inhibition to cytosolic NAT activity and intact mice leukemia cells. Time-course experiments indicated that N-acetylation of AF measured from intact mice leukemia cells were inhibited by aloe-emodin for up to 24h. Using standard steady-state kinetic analysis, it was demonstrated that aloe-emodin was a possible uncompetitive inhibitor to NAT activity in cytosols. The DNA-AF adduct formation in mouse leukemia cells were inhibited by aloe-emodin. The NAT1 mRNA in mouse leukemia cells were also inhibited by aloe-emodin. This report is the first demonstration which showed aloe-emodin affect mice leukemia cells NAT activity, gene expression (NAT1 mRNA) and DNA-AF on adduct formation.

  12. Weak hydrogen bonds formed by thiol groups in N-acetyl-(L)-cysteine and their response to the crystal structure distortion on increasing pressure.

    PubMed

    Minkov, Vasily S; Boldyreva, Elena V

    2013-11-21

    The effect of hydrostatic pressure on single crystals of N-acetyl-l-cysteine was followed at multiple pressure points from 10(-4) to 6.2 GPa with a pressure step of 0.2-0.3 GPa by Raman spectroscopy and X-ray diffraction. Since in the crystals of N-acetyl-l-cysteine the thiol group is involved in intermolecular hydrogen bonds not as a donor only (bonds S-H···O) but also as an acceptor (bonds N-H···S), increasing the pressure does not result in phase transitions. This makes a contrast with the polymorphs of l- and dl-cysteine, in which multiple phase transitions are observed already at relatively low hydrostatic pressures and are related to the changes in the conformation of the thiol side chains only weakly bound to the neighboring molecules in the structure and thus easily switching over the weak S-H···O and S-H···S hydrogen bonds. No phase transitions occur in N-acetyl-l-cysteine with increasing pressure, and changes in cell parameters and volume vs pressure do not reveal any peculiar features. Nevertheless, a more detailed analysis of the changes in intermolecular distances, in particular, of the geometric parameters of the hydrogen bonds based on X-ray single crystal diffraction analysis, complemented by an equally detailed study of the positions of all the significant bands in Raman spectra, allowed us to study the fine details of subtle changes in the hydrogen bond network. Thus, as pressure increases, a continuous shift of the hydrogen atom of the thiol group from one acceptor (a carboxyl group) to another acceptor (a carbonyl group) is observed. Precise single-crystal X-ray diffraction and polarized Raman spectroscopy structural data reveal the formation of a bifurcated S-H···O hydrogen bond with increasing pressure starting with ∼1.5 GPa. The analysis of the vibrational bands in Raman spectra has shown that different donor and acceptor groups start "feeling" the formation of the bifurcated S-H···O hydrogen bond in different pressure

  13. A molecular biomarker for disruption of crustacean molting: the N-acetyl-beta-glucosaminidase mRNA in the epidermis of the fiddler crab.

    PubMed

    Meng, Yanling; Zou, Enmin

    2009-05-01

    Several environmentally persistent chemicals have been found to be capable of disrupting crustacean molting. Considering the importance of molting in the life of crustaceans, there is a need to develop a molecular biomarker that can reflect the disrupting effects of contaminants on ecdysteroid signaling in crustaceans. N-acetyl-beta-glucosaminidase (NAG) is a chitinolytic enzyme found in crustacean epidermis. The results of the present investigation show that the transcription of NAG gene in the epidermis of the fiddler crab, Uca pugilator, is inducible by the molting hormone 20-hydroxyecdysone, which validates the use of NAG mRNA as a biomarker for molt-disrupting effects of xenobiotics.

  14. Elevation of urinary N-acetyl-. beta. -D-glucosaminidase and. beta. -galactosidase activities in workers with long-term exposure to aromatic nitro-amino compounds

    SciTech Connect

    Yoshida, Munehiro; Sunaga, Masahiko; Hara, Ichiro ); Katsumata, Masao; Minami, Masayasu )

    1989-07-01

    Aromatic nitro-amino compounds are used as raw materials of dyes, rubber, pesticides and drugs. A common toxicological reaction to these compounds is the formation of methemoglobin followed by cyanosis and anemia. Little is known about renal damage in workers occupationally exposed to aromatic nitro-amino compounds. Recently, certain urinary enzyme activities have been measured as an index of renal damage. In animal experiments, the activity of urinary N-acetyl-{beta}-D-glucosaminidase (NAG) was increased in rats given p-aminophenol. The authors assay urinary enzyme activities of workers handling aromatic nitro-amino compounds, and discuss the nephrotoxic effects of these compounds used industrially.

  15. Urinary N-acetyl-beta-D-glucosaminidase and beta-aminoisobutyric acid in workers occupationally exposed to metals such as chromium, nickel, and iron.

    PubMed

    Tomokuni, K; Ichiba, M; Hirai, Y

    1993-01-01

    To examine the relationships between the urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and beta-aminoisobutyric acid (AIBA) as a metabolite of thymine, and exposure to chromium, nickel, and iron, we determined these parameters in 58 workers engaged in the cutting and grinding of stainless steel or iron-steel plates. A significant increase in urinary NAG activity or urinary AIBA excretion was found in some of these workers. However, we could not find a significant positive correlation between the urinary excretion of NAG or AIBA and the urinary concentration of chromium, nickel, or iron as an indicator of internal dose.

  16. Biosynthesis and release of beta-endorphin-, N-acetyl beta-endorphin-, beta-endorphin-(1-27)-, and N-acetyl beta-endorphin-(1-27)-like peptides by rat pituitary neurointermediate lobe: beta-endorphin is not further processed by anterior lobe

    SciTech Connect

    Liotta, A.S.; Yamaguchi, H.; Krieger, D.T.

    1981-06-01

    Continuous labeling and pulse-chase techniques were employed to study the synthesis and secretion of multiple forms of immunoreactive beta-endorphin by cultured dispersed rat anterior lobe cells and intact neurointermediate pituitary lobe. Intact neurointermediate lobes incorporated radiolabeled amino acids into four to six forms of immunoreactive beta-endorphin. Four of these forms were physicochemically similar to authentic beta-endorphin, N-acetylated beta-endorphin, beta-endorphin-(1-27), and N-acetylated beta-endorphin-(1-27). Pulse-chase studies indicated that a beta-lipotropin-like molecule served as a metabolic intermediate for a beta-endorphin-like molecule. As beta-endorphin-like material accumulated in the cell, some of it was N-acetylated (approximately 18% at 2 hr chase and approximately 65% at 18 hr chase). At later chase times, beta-endorphin-(1-27)- and N-acetylated beta-endorphin-(1-27)-like peptides were the predominant molecular species detected. All endorphin forms were detected in unlabeled tissue maintained in culture or tissue continuously labeled for 72 hr and were released into the medium under basal, stimulatory (10(-8) M norepinephrine), or inhibitory (10(-7) M dopamine) incubation conditions. In all cases, beta-endorphin-(1-27)-like species were the predominant forms (more than 70% of total) present in the cells and released into the medium. In contrast, approximately 90% of radiolabeled immunoreactive beta-endorphin extracted from anterior lobe cells and medium similarly incubated appeared to represent the authentic beta-endorphin molecule. Continuous labeling (72 hr) revealed the beta-lipotropin/beta-endorphin molar ratio to be approximately 4. We conclude that, in anterior lobe, most of the beta-endorphin is not processed further and is released intact, while in neurointermediate lobe, it serves as a biosynthetic intermediate.

  17. Molecular characterization of the cysJIH promoters of Salmonella typhimurium and Escherichia coli: regulation by cysB protein and N-acetyl-L-serine.

    PubMed Central

    Ostrowski, J; Kredich, N M

    1989-01-01

    The cysJIH promoter regions from Salmonella typhimurium LT7 and Escherichia coli B were cloned and sequenced. Primer extension analyses showed that the major in vivo transcription initiation site in S. typhimurium is located 171 nucleotides upstream of the cysJ start codon. Minor start sites were found 8 and 9 nucleotides downstream of the major site. In vivo transcription initiation in E. coli was found to occur at a single site 66 nucleotides upstream of the cysJ start codon. Primer extension studies also indicated that chromosomal cysJIH transcription is stimulated by sulfur limitation and repressed by growth on L-cystine. Paradoxically, in strains carrying plasmids containing the S. typhimurium cysJIH region, the highest levels of primer extension products were found with RNA from cells grown on L-cystine, even though levels of the proteins encoded by cysJ and cysI were normally repressed. In vitro transcription runoff studies with DNA template from the S. typhimurium cysJIH promoter region showed synthesis of a product originating at the major in vivo start site, which was dependent on the presence of purified cysB protein and either O-acetyl-L-serine or N-acetyl-L-serine. N-Acetyl-L-serine was 10- to 30-fold more active than O-acetyl-L-serine as an in vitro inducer of cysJIH transcription. Images PMID:2701932

  18. N-acetyl-D-glucosamine-asparagine structure in ribosome-inactivating proteins from the seeds of Luffa cylindrica and Phytolacca americana.

    PubMed

    Islam, M R; Kung, S S; Kimura, Y; Funatsu, G

    1991-05-01

    Glycosylation-site-containing peptides were isolated from the proteolytic digests of luffin-a, luffin-b, PAP-S and CNBr-fragments of PAP-S by reverse-phase HPLC, and their amino acid compositions and sequences were analyzed. Six peptides were obtained from luffin-a, and three each from luffin-b and PAP-S. All of these peptides were negative toward the phenol-H2SO4 reaction and gave only N-acetyl-D-glucosamine in gas chromatography after methanolysis and reacetylation. Amounts of N-acetyl-D-glucosamine in these peptides were determined as D-glucosamine to be approximately one mol per peptide by an amino acid analyzer after HCl hydrolysis. Based on these results we concluded that Asn residues at positions of 28, 33, 77, 84, 206, and 227 in luffin-a, of 2, 78, and 85 in luffin-b, and of 10, 44, and 255 in PAP-S were glycosylated with only GlcNAc, and contained one residue per site.

  19. Amino acid sequence and carbohydrate-binding analysis of the N-acetyl-D-galactosamine-specific C-type lectin, CEL-I, from the Holothuroidea, Cucumaria echinata.

    PubMed

    Hatakeyama, Tomomitsu; Matsuo, Noriaki; Shiba, Kouhei; Nishinohara, Shoichi; Yamasaki, Nobuyuki; Sugawara, Hajime; Aoyagi, Haruhiko

    2002-01-01

    CEL-I is one of the Ca2+-dependent lectins that has been isolated from the sea cucumber, Cucumaria echinata. This protein is composed of two identical subunits held by a single disulfide bond. The complete amino acid sequence of CEL-I was determined by sequencing the peptides produced by proteolytic fragmentation of S-pyridylethylated CEL-I. A subunit of CEL-I is composed of 140 amino acid residues. Two intrachain (Cys3-Cys14 and Cys31-Cys135) and one interchain (Cys36) disulfide bonds were also identified from an analysis of the cystine-containing peptides obtained from the intact protein. The similarity between the sequence of CEL-I and that of other C-type lectins was low, while the C-terminal region, including the putative Ca2+ and carbohydrate-binding sites, was relatively well conserved. When the carbohydrate-binding activity was examined by a solid-phase microplate assay, CEL-I showed much higher affinity for N-acetyl-D-galactosamine than for other galactose-related carbohydrates. The association constant of CEL-I for p-nitrophenyl N-acetyl-beta-D-galactosaminide (NP-GalNAc) was determined to be 2.3 x 10(4) M(-1), and the maximum number of bound NP-GalNAc was estimated to be 1.6 by an equilibrium dialysis experiment.

  20. Urinary N-acetyl-β-d-Glucosaminidase Levels are Positively Correlated With 2-Hr Plasma Glucose Levels During Oral Glucose Tolerance Testing in Prediabetes

    PubMed Central

    Ouchi, Motoshi; Suzuki, Tatsuya; Hashimoto, Masao; Motoyama, Masayuki; Ohara, Makoto; Suzuki, Kazunari; Igari, Yoshimasa; Watanabe, Kentaro; Nakano, Hiroshi; Oba, Kenzo

    2012-01-01

    Background Urinary N-acetyl-β-D-glucosaminidase (NAG) excretion is increased in patients with impaired glucose tolerance (IGT). This study investigated when during the oral glucose tolerance test (OGTT) the plasma glucose, urine glucose, and insulin levels correlate most strongly with urinary N-acetyl-β-d-glucosaminidase (NAG) levels in prediabetic subjects. Methods The OGTT was administered to 80 subjects who had not yet received a diagnosis of diabetes mellitus (DM) and in whom HbA1c levels were ≤6.8% and fasting plasma glucose levels were <7.0 mmol/l. Forty-two subjects had normal glucose tolerance (NGT), 31 had impaired glucose tolerance (IGT), and 7 had DM according to World Health Organization criteria. Serum levels of cystatin C, the estimated glomerular filtration rate, the urinary albumin-to-creatinine (Cr) ratio, urinary and serum β2-microglobulin, and urinary NAG were measured as markers of renal function. Results NAG levels were significantly higher in subjects with DM and in subjects with IGT than in subjects with NGT. No significant associations were observed between glycemic status and other markers of renal function. Multiple linear regression analysis showed that the NAG level was positively correlated with plasma glucose levels at 120 min of the OGTT and was associated with the glycemic status of prediabetic patients. Conclusion These results suggest that postprandial hyperglycemia is an independent factor that causes renal tubular damage in prediabetes patients. PMID:23143631

  1. Fe3O4 magnetic core coated by silver and functionalized with N-acetyl cysteine as novel nanoparticles in ferritin adsorption

    NASA Astrophysics Data System (ADS)

    Akduman, Begüm; Uygun, Murat; Uygun, Deniz Aktaş; Antalík, Marián

    2013-04-01

    A novel metal-chelate affinity matrix utilizing N-acetyl cysteine as a metal chelating agent was synthesized. For this, magnetic Fe3O4 core was coated with silver by chemical reduction. Then, these magnetic silver nanoparticles were covered with N-acetyl cysteine, and Fe3+ was chelated to this modified magnetic silver nanoparticle. These magnetic nanoparticles were characterized by SEM, AFM, EDX, and ESR analysis. Synthesized nanoparticles were spherical and average size is found to be 69 nm. Fe3+ chelated magnetic silver nanoparticles were used for the adsorption of ferritin from its aqueous solution. Optimum conditions for the ferritin adsorption experiments were performed at pH 6.0 phosphate buffer and 25 °C of medium temperature and the maximum ferritin adsorption capacity is found to be 89.57 mg/g nanoparticle. Ferritin adsorption onto magnetic silver nanoparticles was increased with increasing ferritin concentration while adsorption capacity was decreased with increasing ionic strength. Affinity of the magnetic silver nanoparticles to the ferritin molecule was shown with SPR analysis. It was also observed that the adsorption capacity of the magnetic silver nanoparticles was not significantly changed after the five adsorption/desorption cycles.

  2. N-acetyl ornithine deacetylase is a moonlighting protein and is involved in the adaptation of Entamoeba histolytica to nitrosative stress

    PubMed Central

    Shahi, Preeti; Trebicz-Geffen, Meirav; Nagaraja, Shruti; Hertz, Rivka; Alterzon-Baumel, Sharon; Methling, Karen; Lalk, Michael; Mazumder, Mohit; Samudrala, Gourinath; Ankri, Serge

    2016-01-01

    Adaptation of the Entamoeba histolytica parasite to toxic levels of nitric oxide (NO) that are produced by phagocytes may be essential for the establishment of chronic amebiasis and the parasite’s survival in its host. In order to obtain insight into the mechanism of E. histolytica’s adaptation to NO, E. histolytica trophozoites were progressively adapted to increasing concentrations of the NO donor drug, S-nitrosoglutathione (GSNO) up to a concentration of 110 μM. The transcriptome of NO adapted trophozoites (NAT) was investigated by RNA sequencing (RNA-seq). N-acetyl ornithine deacetylase (NAOD) was among the 208 genes that were upregulated in NAT. NAOD catalyzes the deacetylation of N-acetyl-L-ornithine to yield ornithine and acetate. Here, we report that NAOD contributes to the better adaptation of the parasite to nitrosative stress (NS) and that this function does not depend on NAOD catalytic activity. We also demonstrated that glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is detrimental to E. histolytica exposed to NS and that this detrimental effect is neutralized by NAOD or by a catalytically inactive NAOD (mNAOD). These results establish NAOD as a moonlighting protein, and highlight the unexpected role of this metabolic enzyme in the adaptation of the parasite to NS. PMID:27808157

  3. Antifibrotic medication using a combination of N-acetyl-L-cystein (NAC) and ACE inhibitors can prevent the recurrence of Dupuytren's disease.

    PubMed

    Knobloch, Karsten; Redeker, Joern; Vogt, Peter M

    2009-11-01

    Dupuytren's disease is a progress fibromatosis of unknown origin first described in 1831. Nonoperative treatment options have been suggested involving radiation therapy, vitamin E, local injection therapy suing calcium channel blockers, interferon, corticosteroids or collagenase. Transforming growth factor-beta1 (TGF-beta1) and its downstream Smad signalling system is well established as a key player during fibrogenesis. A number of in vitro experiments have been assessed the blockade of TGF-beta1 and TGF-beta 2. Clinically, a number of antifibrotic agents are available such as N-acetyl-L-cysteins (NAC) as well as angiotensin-converting enzyme (ACE) inhibitors or AT II antagonists. However, to date none of the well known substances has been tested clinically in fibromatosis such as Dupuytren's disease especially to prevent recurrences after surgical release. Antifibrotic medication using a combination of N-acetyl-L-cystein (NAC) and ACE inhibitor can prevent the recurrence of Dupyutren's disease. Given the fact that recurrence rate in Dupuytren's disease is high and unpredictable after surgical release, an antifibrotic intervention might be worthwhile to consider in the clinical setting. Antifibrotic agents inhibit TGF-beta1, which play a key role in fibromatosis. Thus, antifibrotic medication might reduce the recurrence rate in fibromatosis such as Dupuytren's disease in a clinical significant way.

  4. Quantitative determination of sulfisoxazole and its three N-acetylated metabolites using HPLC-MS/MS, and the saturable pharmacokinetics of sulfisoxazole in mice.

    PubMed

    Oh, Kyungsoo; Baek, Moon-Chang; Kang, Wonku

    2016-09-10

    Sulfisoxazole (SFX) is still used in combination with trimethoprim in cattle despite adverse drug reactions (e.g., urolithiasis). Recently, SFX is known to be a promising repositioned drug candidate for pulmonary hypertension and cancer. We developed a simultaneous determination method of SFX and its N-acetylated metabolites (N(1)-acetyl SFX, N1AS; N(4)-acetyl SFX, N4AS; diacetyl SFX, DAS) using HPLC-MS/MS for the first time, and examined the pharmacokinetics of SFX in mice. N1AS and DAS were converted rapidly to SFX and N4AS, respectively, in mouse plasma. The time courses of plasma SFX and N4AS concentrations were well-characterised following the oral administration of SFX to mice. The absorption, metabolism, and/or excretion of SFX given at >700mg/kg may be saturable, and in contrast to humans and rats, the extent of systemic exposure of mice to N4AS was much greater than that of SFX. Interestingly, the acetyl groups at both N1- and N4-positions were degraded during the ionisation required to generate precursor ions. In additional experiments the carboxyl group of N-acetyl-5-aminosalicylic acid (NA5AS) was lost instead of the acetyl group during the ionisation, and acetaminophen (AAP) appeared. As the acetyl and carboxyl groups of some substances can be degraded during ionisation in the mass spectrometer, caution is appropriate when it is sought to simultaneously quantify similar structures containing these moieties; chromatographic separation is essential.

  5. Acetylated α-Tubulin Regulated by N-Acetyl-Seryl-Aspartyl-Lysyl-Proline(Ac-SDKP) Exerts the Anti-fibrotic Effect in Rat Lung Fibrosis Induced by Silica

    PubMed Central

    Xiaojun, Wang; Yan, Liu; Hong, Xu; Xianghong, Zhang; Shifeng, Li; Dingjie, Xu; Xuemin, Gao; Lijuan, Zhang; Bonan, Zhang; Zhongqiu, Wei; Ruimin, Wang; Brann, Darrell; Fang, Yang

    2016-01-01

    Silicosis is the most serious occupational disease in China. The objective of this study was to screen various proteins related to mechanisms of the pathogenesis of silicosis underlying the anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) using proteomic profile analysis. We also aimed to explore a potential mechanism of acetylated α-tubulin (α-Ac-Tub) regulation by Ac-SDKP. Two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) were used to assess the different protein expression profiles between control and silicosis rats treated with or without Ac-SDKP. Twenty-nine proteins were identified to be potentially involved in the progression of silicosis and the anti-fibrotic effect of Ac-SDKP. Our current study finds that 1) the lost expression of Ac-Tub-α may be a new mechanism in rat silicosis; 2) treatment of silicotic rats with N-acetyl-Seryl-Aspartyl-Lysyl-Proline (Ac-SDKP) inhibits myofibroblast differentiation and collagen deposition accompanied by stabilizing the expression of α-Ac-Tub in vivo and in vitro, which is related with deacetylase family member 6 (HDAC6) and α-tubulin acetyl transferase (α-TAT1). Our data suggest that α-Ac-Tub regulation by Ac-SDKP may potentially be a new anti-fibrosis mechanism. PMID:27577858

  6. Heterodisaccharide 4-O-(N-acetyl-beta-D-glucosaminyl)-D-glucosamine is a specific inducer of chitinolytic enzyme production in Vibrios harboring chitin oligosaccharide deacetylase genes.

    PubMed

    Hirano, Takako; Kadokura, Kazunari; Ikegami, Takanori; Shigeta, Yuko; Kumaki, Yasuko; Hakamata, Wataru; Oku, Tadatake; Nishio, Toshiyuki

    2009-09-01

    Vibrio parahaemolyticus KN1699 produces 4-O-(N-acetyl-beta-d-glucosaminyl)-d-glucosamine (GlcNAc-GlcN) as a major end product from chitin using two extracellular hydrolases: glycoside hydrolase family 18 chitinase, which produces (GlcNAc)(2) from chitin, and carbohydrate esterase (CE) family 4 chitin oligosaccharide deacetylase (COD), which hydrolyzes the N-acetyl group at the reducing-end GlcNAc residue of (GlcNAc)(2). In this study, we clarified that this heterodisaccharide functions as an inducer of the production of the two above-mentioned chitinolytic enzymes, particularly chitinase. Similar results for chitinase production were obtained with other chitin-decomposing Vibrio strains harboring the CE family 4 COD gene; however, such an increase in chitinase production was not observed in chitinolytic Vibrio strains that did not harbor the COD gene. These results suggest that GlcNAc-GlcN is a unique inducer of chitinase production in Vibrio bacteria that have the COD-producing ability and that the COD involved in the synthesis of this signal compound is one of the key enzymes in the chitin catabolic cascade of these bacteria.

  7. Development of a N-acetyl-β-D-glucosaminidase (NAG) assay on a centrifugal lab-on-a-compact-disc (Lab-CD) platform.

    PubMed

    Tanaka, Yoshihide; Okuda, Seira; Sawai, Ayumi; Suzuki, Shigeo

    2012-01-01

    A centrifugal microfluidic platform, which is also known as lab-on-a-compact-disc (Lab-CD), was developed for use as a urinary N-acetyl-β-D-glucosaminidase (NAG) activity assay. In this work, Lab-CD design, centrifugal operations and analytical procedures were established. Automated liquid handling on Lab-CD processes, such as fluid transport, sample metering, mixing, and fluorescence detection are accomplished using a portable Lab-CD system. The linearity of the NAG assay using 4-methylumbelliferyl-N-acetyl-β-D-glucosaminide (4-MU-GlcNAc) was found to be acceptable in the range of 2.5 to 20 U L(-1); the relative standard deviations for the fluorescence intensity of eight samples (7.5 U L(-1)) was 6.4%. Clinical diagnostics is one of the most promising applications for Lab-CD technologies. All the benefits of miniaturization, such as reduced sample requirement, reduced reagent consumption and automation, are realized in this investigation.

  8. A Ribbon-like Structure in the Ejective Organelle of the Green Microalga Pyramimonas parkeae (Prasinophyceae) Consists of Core Histones and Polymers Containing N-acetyl-glucosamine.

    PubMed

    Yamagishi, Takahiro; Kurihara, Akira; Kawai, Hiroshi

    2015-11-01

    The green microalga, Pyramimonas parkeae (Prasinophyceae) has an ejective organelle containing a coiled ribbon structure resembling the ejectisome in Cryptophyta. This structure is discharged from the cell by a stimulus and extends to form a tube-like structure, but the molecular components of the structure have not been identified. Tricine-SDS-PAGE analysis indicated that the ribbon-like structure of P. parkeae contains some proteins and low molecular acidic polymers. Edman degradation, LC/MS/MS analyses and immunological studies demonstrated that their proteins are core histones (H3, H2A, H2B and H4). In addition, monosaccharide composition analysis of the ribbon-like structures and degradation by lysozyme strongly indicated that the ribbon-like structure consist of β (1-4) linked polymers containing N-acetyl-glucosamine. Purified polymers and recombinant histones formed glob-like or filamentous structures. Therefore we conclude that the ribbon-like structure of P. parkeae mainly consists of a complex of core histones (H3, H2A, H2B and H4) and polymers containing N-acetyl-glucosamine, and suggest to name the ejective organelle in P. parkeae the "histrosome" to distinguish it from the ejectisome in Cryptophyta.

  9. N-acetyl ornithine deacetylase is a moonlighting protein and is involved in the adaptation of Entamoeba histolytica to nitrosative stress.

    PubMed

    Shahi, Preeti; Trebicz-Geffen, Meirav; Nagaraja, Shruti; Hertz, Rivka; Alterzon-Baumel, Sharon; Methling, Karen; Lalk, Michael; Mazumder, Mohit; Samudrala, Gourinath; Ankri, Serge

    2016-11-03

    Adaptation of the Entamoeba histolytica parasite to toxic levels of nitric oxide (NO) that are produced by phagocytes may be essential for the establishment of chronic amebiasis and the parasite's survival in its host. In order to obtain insight into the mechanism of E. histolytica's adaptation to NO, E. histolytica trophozoites were progressively adapted to increasing concentrations of the NO donor drug, S-nitrosoglutathione (GSNO) up to a concentration of 110 μM. The transcriptome of NO adapted trophozoites (NAT) was investigated by RNA sequencing (RNA-seq). N-acetyl ornithine deacetylase (NAOD) was among the 208 genes that were upregulated in NAT. NAOD catalyzes the deacetylation of N-acetyl-L-ornithine to yield ornithine and acetate. Here, we report that NAOD contributes to the better adaptation of the parasite to nitrosative stress (NS) and that this function does not depend on NAOD catalytic activity. We also demonstrated that glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is detrimental to E. histolytica exposed to NS and that this detrimental effect is neutralized by NAOD or by a catalytically inactive NAOD (mNAOD). These results establish NAOD as a moonlighting protein, and highlight the unexpected role of this metabolic enzyme in the adaptation of the parasite to NS.

  10. Design and optimization of aspartate N-acetyltransferase inhibitors for the potential treatment of Canavan disease.

    PubMed

    Thangavelu, Bharani; Mutthamsetty, Vinay; Wang, Qinzhe; Viola, Ronald E

    2017-02-01

    Canavan disease is a fatal neurological disorder caused by defects in the metabolism of N-acetyl-l-aspartate (NAA). Recent work has shown that the devastating symptoms of this disorder are correlated with the elevated levels of NAA observed in these patients, caused as a consequence of the inability of mutated forms of aspartoacylase to adequately catalyze its breakdown. The membrane-associated enzyme responsible for the synthesis of NAA, aspartate N-acetyltransferase (ANAT), has recently been purified and examined (Wang et al., Prot Expr Purif. 2016;119:11). With the availability, for the first time, of a stable and soluble form of ANAT we can now report the identification of initial inhibitors against this biosynthetic enzyme, obtained from the screening of several focused compound libraries. Two core structures of these moderate binding compounds have subsequently been optimized, with the most potent inhibitors in these series possessing sub-micromolar inhibition constants (Ki values) against ANAT. Slowing the production of NAA via the inhibition of ANAT will lower the elevated levels of this metabolite and can potentially serve as a treatment option to moderate the symptoms of Canavan disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. 21 CFR 582.5017 - Aspartic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aspartic acid. 582.5017 Section 582.5017 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5017 Aspartic acid. (a) Product. Aspartic acid (L- and DL-forms). (b) Conditions of use...

  12. 21 CFR 582.5017 - Aspartic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aspartic acid. 582.5017 Section 582.5017 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5017 Aspartic acid. (a) Product. Aspartic acid (L- and DL-forms). (b) Conditions of use...

  13. 21 CFR 582.5017 - Aspartic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aspartic acid. 582.5017 Section 582.5017 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5017 Aspartic acid. (a) Product. Aspartic acid (L- and DL-forms). (b) Conditions of use...

  14. 21 CFR 582.5017 - Aspartic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aspartic acid. 582.5017 Section 582.5017 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5017 Aspartic acid. (a) Product. Aspartic acid (L- and DL-forms). (b) Conditions of use...

  15. 21 CFR 582.5017 - Aspartic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aspartic acid. 582.5017 Section 582.5017 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5017 Aspartic acid. (a) Product. Aspartic acid (L- and DL-forms). (b) Conditions of use...

  16. Inhibition of lung tumorigenesis in A/J mice by N-acetyl-S-(N-2-phenethylthiocarbamoyl)-L-cysteine and myo-inositol, individually and in combination.

    PubMed

    Hecht, Stephen S; Upadhyaya, Pramod; Wang, Mingyao; Bliss, Robin L; McIntee, Edward J; Kenney, Patrick M J

    2002-09-01

    Isothiocyanates, their N-acetylcysteine conjugates, and myo-inositol (MI) are inhibitors of lung tumorigenesis in A/J mice. However, chemoprevention by combinations of these compounds in different temporal sequences has not been examined. This is important for developing practical approaches to lung cancer chemoprevention in smokers and ex-smokers. We used a tumor model in which A/J mice are treated with 8 weekly doses of benzo[a]pyrene (B[a]P) plus 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and killed 19 weeks after the final treatment. In Experiment 1, isothiocyanates or their N-acetylcysteine conjugates were added to the diet (1 or 3 micro mol/g) from 1 week before until 1 week after carcinogen treatment. The compounds were 2-phenethyl isothiocyanate (PEITC), 3-phenylpropyl isothiocyanate (PPITC), N-acetyl-S-(N-benzyl-thiocarbamoyl)-L-cysteine (BITC-NAC), N-acetyl-S-(N-2-phenethylthiocarbamoyl)-L-cysteine (PEITC-NAC), and N-acetyl-S-(N-3-phenylpropylthiocarbamoyl)-L-cysteine (PPITC-NAC). Significant reductions in lung tumor multiplicity were observed in mice treated with PEITC, PEITC-NAC, PPITC and PPITC-NAC. PEITC-NAC was chosen for combination studies with MI (Experiment 2). Mice were treated with B[a]P plus NNK without or with PEITC-NAC (3 micro mol/g diet), MI (55.5 micro mol/g diet), or PEITC-NAC plus MI (3 micro mol plus 55.5 micro mol/g diet). Different temporal sequences of dietary additions were investigated: carcinogen treatment phase; post-carcinogen treatment phase; entire experiment; 50% of carcinogen treatment phase until termination; and 75% of carcinogen treatment phase until termination. All treatments reduced lung tumor multiplicity except PEITC-NAC post-carcinogen or from 75% of the carcinogen treatment phase. Reduction of lung tumor multiplicity by PEITC-NAC plus MI was greater than that in the mice treated with the agents alone in all temporal sequences. When all results were combined, PEITC-NAC plus MI was significantly more

  17. Four homochiral coordination polymers contain N-acetyl-L-tyrosine and different N-donor ligand: Influence of metal cations, ancillary ligands and coordination modes

    SciTech Connect

    Li, Meng-Li; Song, Hui-Hua

    2013-10-15

    Using the chiral ligand N-acetyl-L-tyrosine (Hacty) and maintaining identical reaction conditions, Zn(II), Co(II), and Cd(II) salts provided four novel homochiral coordination polymers ([Zn(acty)(bipy){sub 2}(H{sub 2}O){sub 2}]·NO{sub 3}·2H{sub 2}O){sub n}1, ([Co(acty)(bipy){sub 2}(H{sub 2}O){sub 2}]·NO{sub 3}·2H{sub 2}O){sub n}2, ([Cd(acty){sub 2}(bipy)H{sub 2}O]·H{sub 2}O){sub n}3, and ([Cd(acty)(bpe){sub 2}(Ac)]·6H{sub 2}O){sub n}4 (bipy=4,4′-bipyridine; bpe=1,2-di(4-pyridyl)ethane) in the presence of ancillary ligands. Compounds 1 and 2 are isostructural 1D chain structures. The neighboring chains are further linked into a 3D supramolecular structure via π⋯π stacking and hydrogen bond interactions. Compound 3 shows a 2D network and 4 generates 1D infinite chains along the c-axis. Compounds 3 and 4 are further connected into 3D supramolecular network by hydrogen bond interactions. More importantly, coordination in acyl oxygen atoms and ancillary ligands (bpe) as monodentate decorating ligands in 4 are rarely reported. Ancillary ligands and metal cations significantly influence the structure of the complexes. The photoluminescence properties of 1, 3, and 4 were studied at room temperature. Circular dichroism (CD) of the complexes have been investigated. - Graphical abstract: Four new homochiral coordination polymers were prepared and structurally characterized, which investigate the influence of the ancillary ligands and metal ions on the design and synthesis of coordination polymers. Display Omitted - Highlights: • It is rarely reported that the chiral coordination polymers prepared with N-acetyl-L-tyrosine ligands. • The alkalescent acetyl oxygen atom is difficult to participate in coordination but it is happened in the N-acetyl-L-tyrosine ligands. • The ancillary ligands (4,4′-bipy and bpe) are present in an unusual coordination modes, monodentate decorating ligands in 1, 2 and 4. • Structure comparative analyses results indicate that the

  18. Microbial production of N-acetyl cis-4-hydroxy-L-proline by coexpression of the Rhizobium L-proline cis-4-hydroxylase and the yeast N-acetyltransferase Mpr1.

    PubMed

    Bach, Thi Mai Hoa; Hara, Ryotaro; Kino, Kuniki; Ohtsu, Iwao; Yoshida, Nobuyuki; Takagi, Hiroshi

    2013-01-01

    The proline analogue cis-4-hydroxy-L-proline (CHOP), which inhibits the biosynthesis of collagen, has been clinically evaluated as an anticancer drug, but its water solubility and low molecular weight limits its therapeutic potential since it is rapidly excreted. In addition, CHOP is too toxic to be practical as an anticancer drug, due primarily to its systematic effects on noncollagen proteins. To promote CHOP's retention in blood and/or to decrease its toxicity, N-acetylation of CHOP might be a novel approach as a prodrug. The present study was designed to achieve the microbial production of N-acetyl CHOP from L-proline by coexpression of L-proline cis-4-hydroxylases converting L-proline into CHOP (SmP4H) from the Rhizobium Sinorhizobium meliloti and N-acetyltransferase converting CHOP into N-acetyl CHOP (Mpr1) from the yeast Saccharomyces cerevisiae. We constructed a coexpression plasmid harboring both the SmP4H and Mpr1 genes and introduced it into Escherichia coli BL21(DE3) or its L-proline oxidase gene-disrupted (ΔputA) strain. M9 medium containing L-proline produced more N-acetyl CHOP than LB medium containing L-proline. E. coli ΔputA cells accumulated L-proline (by approximately 2-fold) compared to that in wild-type cells, but there was no significant difference in CHOP production between wild-type and ΔputA cells. The addition of NaCl and L-ascorbate resulted in a 2-fold increase in N-acetyl CHOP production in the L-proline-containing M9 medium. The highest yield of N-acetyl CHOP was achieved at 42 h cultivation in the optimized medium. Five unknown compounds were detected in the total protein reaction, probably due to the degradation of N-acetyl CHOP. Our results suggest that weakening of the degradation or deacetylation pathway improves the productivity of N-acetyl CHOP.

  19. Insight into hydrolytic reaction of N-acetylated L-histidylglycine dipeptide with novel mechlorethamine platinum(II) complex. NMR and DFT study of the hydrolytic reaction.

    PubMed

    Petrović, Zorica D; Petrović, Vladimir P; Simijonović, Dušica; Marković, Svetlana

    2011-09-28

    The reaction of K(2)PtCl(4) with the alkylating agent mechlorethamine hydrochloride, at a molar ratio of 1:2, results in the formation of 2-chloro-N-(2-chloroethyl)-N-methylethylammonium-tetrachloridoplatinate(II) complex. The hydrolytic activity of the novel Pt(II) complex was tested in the reaction with N-acetylated L-histidylglycine dipeptide at a molar ratio 1:1. It was shown that the hydrolytic reaction, performed at 60 °C in acidic medium, leads to the regioselective cleavage of the amide bond involving the carboxylic group of histidine. Density functional theory was used to explore the structures of the proposed participants in the hydrolytic reaction.

  20. Fourier transform infrared spectra and molecular structure of 5-methoxytryptamine, N-acetyl-5-methoxytryptamine and N-phenylsulfonamide-5-methoxytryptamine

    NASA Astrophysics Data System (ADS)

    Bayari, S.; Ide, S.

    2003-04-01

    5-Methoxytryptamine (5-MT) is a potent antioxidant and has radioprotective action. N-acetyl-5-methoxytryptamine (melatonin, NA-5-MT) is a free radical scavenger and antioxidant, which protects against oxidative damage due to a variety of toxicants. The infrared spectra of 5-MT, NA-5-MT and new synthesized N-phenylsulfonamide-5-methoxytryptamine (PS-5-MT) were investigated in the region between 4000 and 400 cm -1. Vibrational assignments of the molecules have been made for fundamental modes on the basis of the group vibrational concept, infrared intensity and comparison with the assignments for related molecules. X-ray powder diffraction patterns of molecules were also recorded. In order to optimize the geometries of the molecules, molecular mechanic calculations (MM3) were performed. Conformational analysis of 5-MT, NA-5-MT and PS-5-MT was also established by the using PM3 method.

  1. The SPASIBA force field for chondroitin sulfate: vibrational analysis of D-glucuronic and N-acetyl-D-galactosamine 4-sulfate sodium salts.

    PubMed

    Meziane-Tani, M; Lagant, P; Semmoud, A; Vergoten, G

    2006-10-05

    Normal-mode analyses were carried out on the two components of the chondroitin 4-sulfate linear glycosaminoglycan, a copolymer implying alternate D-glucuronate beta-(1-->3) and N-acetyl-D-galactosamine 4-sulfate beta-(1-->4) (hereafter named D-galactosamine 4-sulfate) residues. Scaled quantum mechanical calculations (SQM) using the density functional theory approach at different levels of theory (B3LYP/6-31G** and B3LYP/6-31++G**) were performed to obtain correct vibrational assignments. The SPASIBA empirical force field parameters were then obtained from both theoretical predictions and observed IR and Raman data. It is shown that calculations including diffuse functions at the B3LP/6-31++G** level and the introduction of the Na+ counterion are necessary to give correct assignments of the CO2- symmetric (nu(s)) and antisymmetric (nu(a)) stretching modes for the glucuronic carboxylate residue.

  2. The Interaction of a Carbohydrate-Binding Module from a Clostridium perfringens N-Acetyl-beta-hexosaminidase with its Carbohydrate Receptor

    SciTech Connect

    Ficko-Blean,E.; Boraston, A.

    2006-01-01

    Clostridium perfringens is a notable colonizer of the human gastrointestinal tract. This bacterium is quite remarkable for a human pathogen by the number of glycoside hydrolases found in its genome. The modularity of these enzymes is striking as is the frequent occurrence of modules having amino acid sequence identity with family 32 carbohydrate-binding modules (CBMs), often referred to as F5/8 domains. Here we report the properties of family 32 CBMs from a C. perfringens N-acetyl-{beta}-hexosaminidase. Macroarray, UV difference, and isothermal titration calorimetry binding studies indicate a preference for the disaccharide LacNAc ({beta}-d-galactosyl-1,4-{beta}-d-N-acetylglucosamine). The molecular details of the interaction of this CBM with galactose, LacNAc, and the type II blood group H-trisaccharide are revealed by x-ray crystallographic studies at resolutions of 1.49, 2.4, and 2.3 Angstroms, respectively.

  3. Purification and characterization of an endo-N-acetyl-beta-D-glucosaminidase from the culture medium of Stigmatella aurantiaca DW4.

    PubMed Central

    Bourgerie, S; Karamanos, Y; Grard, T; Julien, R

    1994-01-01

    A novel endo-N-acetyl-beta-D-glucosaminidase (ENGase), acting on the di-N-acetylchitobiosyl part of N-linked glycans, was characterized in the culture medium of Stigmatella aurantiaca DW4. Purified to homogeneity by ammonium sulfate precipitation, gel filtration, and chromatofocusing, this ENGase presents, upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a molecular mass near 27 kDa. Optimal pH and pI were 4.0 and 6.8, respectively. The enzyme, named ENGase St, exhibits high activity on oligomannoside-type glycoasparagines and glycoproteins and could also hydrolyze hybrid- and complex-type glycoasparagines but does not acts as a murein hydrolase. Images PMID:7928985

  4. EPR investigation of gamma-irradiated L-citrulline, α-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine

    NASA Astrophysics Data System (ADS)

    Osmanoğlu, Y. Emre; Sütçü, Kerem; Başkan, M. Halim

    2017-02-01

    The spectroscopic parameters of the paramagnetic species produced in gamma-irradiated L-citrulline, α-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine were investigated at room temperature at a dose of 20 kGy by using EPR technique. The paramagnetic species were attributed to NH2CONH(CH2)3ĊNH2COOH, HOCH2ĊCH3COOH and HOĊHCCH3NH2COOH, CH3CH3ĊCHNH2COOH and SHCH2ĊNHCOCH3COOH radicals, respectively. EPR data of the unpaired electron with the environmental protons and 14N nucleus were used to characterize the contributing radicals produced in gamma irradiated compounds. In this paper, the stability of these compounds at room temperature after irradiation was also studied.

  5. Studies on the chemical modification of the essential groups of N-Acetyl-beta-D-glucosaminidase from viscera of green crab (Scylla Serrata).

    PubMed

    Jin, Zhu-Xing; Zhang, Ji-Ping; Yan, Ya-Wen; Wang, Qin

    2008-05-01

    The chemical modification of N-acetyl-beta-D: -glucosaminidase (EC3.2.1.30) from viscera of green crab (Scylla serrata) has been first studied. The modification of indole groups of tryptophan of the enzyme by N-bromosuccinimide can lead to complete inactivation, accompanying the absorption decreasing at 275 nm and the fluorescence intensity quenching at 338 nm, indicating that tryptophan is essential residue to the enzyme. The modification of histidine residue, the carboxyl groups, and lysine residue inactivates the enzyme completely or incompletely. The results show that imidazole groups of histidine residue or sulfhydryl residues, the carboxyl groups of acidic amino acid, amino groups of lysine residue, and indole groups of tryptophan were essential for the catalytic activity of enzyme, while the results demonstrate that the disulfide bonds and the carbamidine groups of arginine residues are not essential to the enzyme's function.

  6. Structure of the N-acetyl-L-rhamnosamine-containing O-polysaccharide of Proteus vulgaris TG 155 from a new Proteus serogroup, O55.

    PubMed

    Kondakova, Anna N; Kolodziejska, Katarzyna; Zych, Krystyna; Senchenkova, Sof'ya N; Shashkov, Alexander S; Knirel, Yuriy A; Sidorczyk, Zygmunt

    2003-09-10

    The O-polysaccharide of the lipopolysaccharide (LPS) of Proteus vulgaris TG 155 was found to contain 2-acetamido-2,6-dideoxy-L-mannose (N-acetyl-L-rhamnosamine, L-RhaNAc), a monosaccharide that occurs rarely in Nature. The following structure of the O-polysaccharide was established by NMR spectroscopy, including 2D COSY, TOCSY, ROESY and 1H,13C HSQC experiments, along with chemical methods: [carbohydrate structure in text] Rabbit polyclonal O-antiserum against P. vulgaris TG 155 reacted with both core and O-polysaccharide moieties of the homologous LPS but showed no cross-reactivity with other LPS from the complete set of serologically different Proteus strains. Based on the unique O-polysaccharide structure and the serological data, we propose classifying P. vulgaris TG 155 into a new, separate Proteus O-serogroup, O55.

  7. Role of mitochondria and NADPH oxidase derived reactive oxygen species in hyperoxaluria induced nephrolithiasis: therapeutic intervention with combinatorial therapy of N-acetyl cysteine and Apocynin.

    PubMed

    Sharma, Minu; Kaur, Tanzeer; Singla, S K

    2016-03-01

    The interactions between the main cellular sources of ROS, such as mitochondria and NADPH oxidase, are known to play an imperative role in the pathogenesis of hyperoxaluria-induced nephrolithiasis. The present study was designed to investigate the protective effect of a combinatorial therapy based on the attenuation of oxidative stress with antioxidant (N-acetyl cysteine), and NADPH oxidase inhibitor (apocynin), that might be required to effectively eliminate hyperoxaluric manifestations. Hyperoxaluria was induced in male Wistar rats by administering 0.4% ethylene glycol with 1% ammonium chloride in drinking water for 9 days. Hyperoxaluria accentuated renal oxidative stress in terms of increased ROS production and lipid peroxidation. Mitochondrial dysfunction, a central deleterious event in renal stone crystallization, was evident by decreased activities of electron transport chain complex I, II and IV, augmented mitochondrial ROS, reduced GSH/GSSG ratio, which resulted in the mitochondrial permeability transition pore (mPTP) opening as indicated by increased mitochondrial swelling in hyperoxaluric rats. Furthermore, NADPH oxidase activity was significantly increased, with raised expression of NOX1, NOX2, NOX4, p38MAPK and MnSOD, in the renal tissue of hyperoxaluric rats compared to control. However, combinatorial therapy with N-acetyl cysteine (50mg/kg/day) and apocynin (200mg/kg/day), intraperitoneally, significantly improved renal functions in hyperoxaluric rats and considerably ameliorated mitochondrial dysfunction. NAC with apocynin was also found to be effective in reducing the redundant activity of NADPH oxidase in renal tissue of hyperoxaluric rats. Hence, our investigation provides novel mechanistic insights that combinatorial approaches using targeted modulators of ROS offer therapeutic benefits in hyperoxaluria-induced nephrolithiasis.

  8. The activity of N-acetyl-β-d-hexosaminidase A and B and β-glucuronidase in nasal polyps and hypertrophic nasal concha.

    PubMed

    Chojnowska, Sylwia; Minarowska, Alina; Waszkiewicz, Napoleon; Kępka, Alina; Zalewska-Szajda, Beata; Gościk, Elżbieta; Kowal, Krzysztof; Olszewska, Ewa; Konarzewska-Duchnowska, Emilia; Minarowski, Łukasz; Zwierz, Krzysztof; Ładny, Jerzy Robert; Szajda, Sławomir Dariusz

    2014-01-01

    Nasal polyps and hypertrophic lower nasal conchae are common disorders of nasal cavity. The majority of etiopathogenetic theories indicate inflammatory background of polyps and hypertrophic concha. N-acetyl-β-D-hexosaminidase and β-glucuronidase are lysosomal exoglycosidases revealing accelerated activity in inflammatory processes. The aim of the study was to evaluate the catabolism of glycoconjugates in nasal polyps and hypertrophic nasal concha basing on the activity of N-acetyl-β-D-hexosaminidase (HEX) and β-glucuronidase (GLU). Material consisted of nasal polyps taken from 40 patients during polypectomy in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and hypertrophic lower nasal conchae taken from 20 patients during mucotomy. The activity of HEX, HEX A, HEX B and GLU in supernatant of homogenates of nasal polyps and hypertrophic lower nasal concha tissues has been estimated using colorimetric method. Statistically significant decrease has been observed in concentration of the activity (per 1mg of tissue) of HEX (p<0.05), HEX B (p<0.001) and specific activity (per 1mg of protein) of HEX B (p<0.001) in nasal polyps tissue in comparison to hypertrophic lower nasal conchae tissue. Decrease in the activity and specific activity concentration of the majority of examined lysosomal exoglycosidases (increasing in inflammations) in comparison to hypertrophic lower nasal conchae suggests electrolytes disorders and questions the inflammatory background of nasal polyps. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  9. Quantification of the neurotransmitters melatonin and N-acetyl-serotonin in human serum by supercritical fluid chromatography coupled with tandem mass spectrometry.

    PubMed

    Wolrab, Denise; Frühauf, Peter; Gerner, Christopher

    2016-09-21

    The aim of this study was developing a supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) method and an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method, for the analysis of N-acetyl-serotonin (NAS) and melatonin (Mel) in human serum, and to compare the performance of these methods. Deuterated isotopologues of the neurotransmitters were synthesized and evaluated for suitability as internal standards in sample preparation. Liquid-liquid extraction was selected as sample preparation procedure. With chloroform, the best extraction solvent tested, an extraction yield of 48 ± 2% for N-acetyl-serotonin and 101 ± 10% for melatonin was achieved. SFC separation was accomplished within 3 min on a BEH stationary phase, employing isocratic elution with 90% carbon dioxide and 0.1% formic acid as well as 0.05% ammonium formate in methanol. For the 4 min UHPLC gradient separation with 0.1% formic acid in water and methanol, respectively, a Kinetex XB-C18 was used as stationary phase. Both chromatographic techniques were optimized regarding mobile phase composition, additives to the mobile phase and column temperature. Multiple reaction monitoring (MRM) analysis was used for quantification of the metabolites. Both methods were validated regarding retention time stability, LOD, LOQ, repeatability and reproducibility of quantification, process efficiency, extraction recovery and matrix effects. LOD and LOQ were 0.017 and 0.05 pg μL(-1) for NAS and 0.006 and 0.018 pg μL(-1) for Mel in SFC-MS/MS compared to 0.028 and 0.1 pg μL(-1) for NAS and 0.006 and 0.017 pg μL(-1) for Mel in UHPLC-MS/MS. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Identification of Novel Potential β-N-Acetyl-D-Hexosaminidase Inhibitors by Virtual Screening, Molecular Dynamics Simulation and MM-PBSA Calculations

    PubMed Central

    Liu, Jianling; Liu, Mengmeng; Yao, Yao; Wang, Jinan; Li, Yan; Li, Guohui; Wang, Yonghua

    2012-01-01

    Chitinolytic β-N-acetyl-d-hexosaminidases, as a class of chitin hydrolysis enzyme in insects, are a potential species-specific target for developing environmentally-friendly pesticides. Until now, pesticides targeting chitinolytic β-N-acetyl-d-hexosaminidase have not been developed. This study demonstrates a combination of different theoretical methods for investigating the key structural features of this enzyme responsible for pesticide inhibition, thus allowing for the discovery of novel small molecule inhibitors. Firstly, based on the currently reported crystal structure of this protein (OfHex1.pdb), we conducted a pre-screening of a drug-like compound database with 8 × 106 compounds by using the expanded pesticide-likeness criteria, followed by docking-based screening, obtaining 5 top-ranked compounds with favorable docking conformation into OfHex1. Secondly, molecular docking and molecular dynamics simulations are performed for the five complexes and demonstrate that one main hydrophobic pocket formed by residues Trp424, Trp448 and Trp524, which is significant for stabilization of the ligand–receptor complex, and key residues Asp477 and Trp490, are respectively responsible for forming hydrogen-bonding and π–π stacking interactions with the ligands. Finally, the molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) analysis indicates that van der Waals interactions are the main driving force for the inhibitor binding that agrees with the fact that the binding pocket of OfHex1 is mainly composed of hydrophobic residues. These results suggest that screening the ZINC database can maximize the identification of potential OfHex1 inhibitors and the computational protocol will be valuable for screening potential inhibitors of the binding mode, which is useful for the future rational design of novel, potent OfHex1-specific pesticides. PMID:22605995

  11. Characterization of the chemical reactivity and nephrotoxicity of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine sulfoxide, a potential reactive metabolite of trichloroethylene.

    PubMed

    Irving, Roy M; Pinkerton, Marie E; Elfarra, Adnan A

    2013-02-15

    N-Acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NA-DCVC) has been detected in the urine of humans exposed to trichloroethylene and its related sulfoxide, N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (NA-DCVCS), has been detected as hemoglobin adducts in blood of rats dosed with S-(1,2-dichlorovinyl)-L-cysteine (DCVC) or S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (DCVCS). Because the in vivo nephrotoxicity of NA-DCVCS was unknown, in this study, male Sprague-Dawley rats were dosed (i.p.) with 230 μmol/kg b.w. NA-DCVCS or its potential precursors, DCVCS or NA-DCVC. At 24 h post treatment, rats given NA-DCVC or NA-DCVCS exhibited kidney lesions and effects on renal function distinct from those caused by DCVCS. NA-DCVC and NA-DCVCS primarily affected the cortico-medullary proximal tubules (S(2)-S(3) segments) while DCVCS primarily affected the outer cortical proximal tubules (S(1)-S(2) segments). When NA-DCVCS or DCVCS was incubated with GSH in phosphate buffer pH 7.4 at 37°C, the corresponding glutathione conjugates were detected, but NA-DCVC was not reactive with GSH. Because NA-DCVCS exhibited a longer half-life than DCVCS and addition of rat liver cytosol enhanced GSH conjugate formation, catalysis of GSH conjugate formation by the liver could explain the lower toxicity of NA-DCVCS in comparison with DCVCS. Collectively, these results provide clear evidence that NA-DCVCS formation could play a significant role in DCVC, NA-DCVC, and trichloroethylene nephrotoxicity. They also suggest a role for hepatic metabolism in the mechanism of NA-DCVC nephrotoxicity.

  12. Catalysis by N-Acetyl-d-glucosaminylphosphatidylinositol De-N-acetylase (PIG-L) from Entamoeba histolytica

    PubMed Central

    Ashraf, Mohammad; Sreejith, Perinthottathil; Yadav, Usha; Komath, Sneha Sudha

    2013-01-01

    We showed previously that Entamoeba histolytica PIG-L exhibits a novel metal-independent albeit metal-stimulated activity. Using mutational and biochemical analysis, here we identify Asp-46 and His-140 of the enzyme as being important for catalysis. We show that these mutations neither affect the global conformational of the enzyme nor alter its metal binding affinity. The defect in catalysis, due to the mutations, is specifically due to an effect on Vmax and not due to altered substrate affinity (or Km). We propose a general acid-base pair mechanism to explain our results. PMID:23341455

  13. Characterization of the chemical reactivity and nephrotoxicity of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine sulfoxide, a potential reactive metabolite of trichloroethylene

    SciTech Connect

    Irving, Roy M.; Pinkerton, Marie E.; Elfarra, Adnan A.

    2013-02-15

    N-Acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NA-DCVC) has been detected in the urine of humans exposed to trichloroethylene and its related sulfoxide, N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (NA-DCVCS), has been detected as hemoglobin adducts in blood of rats dosed with S-(1,2-dichlorovinyl)-L-cysteine (DCVC) or S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (DCVCS). Because the in vivo nephrotoxicity of NA-DCVCS was unknown, in this study, male Sprague–Dawley rats were dosed (i.p.) with 230 μmol/kg b.w. NA-DCVCS or its potential precursors, DCVCS or NA-DCVC. At 24 h post treatment, rats given NA-DCVC or NA-DCVCS exhibited kidney lesions and effects on renal function distinct from those caused by DCVCS. NA-DCVC and NA-DCVCS primarily affected the cortico-medullary proximal tubules (S{sub 2}–S{sub 3} segments) while DCVCS primarily affected the outer cortical proximal tubules (S{sub 1}–S{sub 2} segments). When NA-DCVCS or DCVCS was incubated with GSH in phosphate buffer pH 7.4 at 37 °C, the corresponding glutathione conjugates were detected, but NA-DCVC was not reactive with GSH. Because NA-DCVCS exhibited a longer half-life than DCVCS and addition of rat liver cytosol enhanced GSH conjugate formation, catalysis of GSH conjugate formation by the liver could explain the lower toxicity of NA-DCVCS in comparison with DCVCS. Collectively, these results provide clear evidence that NA-DCVCS formation could play a significant role in DCVC, NA-DCVC, and trichloroethylene nephrotoxicity. They also suggest a role for hepatic metabolism in the mechanism of NA-DCVC nephrotoxicity. - Highlights: ► NA-DCVCS and NA-DCVC toxicity are distinct from DCVCS toxicity. ► NA-DCVCS readily reacts with GSH to form mono- and di-GSH conjugates. ► Liver glutathione S-transferases enhance NA-DCVCS GSH conjugate formation. ► Renal localization of lesions suggests a role for NA-DCVCS in TCE nephrotoxicity.

  14. Amelioration of acute sequelae of blast induced mild traumatic brain injury by N-acetyl cysteine: a double-blind, placebo controlled study.

    PubMed

    Hoffer, Michael E; Balaban, Carey; Slade, Martin D; Tsao, Jack W; Hoffer, Barry

    2013-01-01

    Mild traumatic brain injury (mTBI) secondary to blast exposure is the most common battlefield injury in Southwest Asia. There has been little prospective work in the combat setting to test the efficacy of new countermeasures. The goal of this study was to compare the efficacy of N-acetyl cysteine (NAC) versus placebo on the symptoms associated with blast exposure mTBI in a combat setting. This study was a randomized double blind, placebo-controlled study that was conducted on active duty service members at a forward deployed field hospital in Iraq. All symptomatic U.S. service members who were exposed to significant ordnance blast and who met the criteria for mTBI were offered participation in the study and 81 individuals agreed to participate. Individuals underwent a baseline evaluation and then were randomly assigned to receive either N-acetyl cysteine (NAC) or placebo for seven days. Each subject was re-evaluated at 3 and 7 days. Outcome measures were the presence of the following sequelae of mTBI: dizziness, hearing loss, headache, memory loss, sleep disturbances, and neurocognitive dysfunction. The resolution of these symptoms seven days after the blast exposure was the main outcome measure in this study. Logistic regression on the outcome of 'no day 7 symptoms' indicated that NAC treatment was significantly better than placebo (OR = 3.6, p = 0.006). Secondary analysis revealed subjects receiving NAC within 24 hours of blast had an 86% chance of symptom resolution with no reported side effects versus 42% for those seen early who received placebo. This study, conducted in an active theatre of war, demonstrates that NAC, a safe pharmaceutical countermeasure, has beneficial effects on the severity and resolution of sequelae of blast induced mTBI. This is the first demonstration of an effective short term countermeasure for mTBI. Further work on long term outcomes and the potential use of NAC in civilian mTBI is warranted. ClinicalTrials.gov NCT00822263.

  15. Amelioration of Acute Sequelae of Blast Induced Mild Traumatic Brain Injury by N-Acetyl Cysteine: A Double-Blind, Placebo Controlled Study

    PubMed Central

    Slade, Martin D.; Tsao, Jack W.; Hoffer, Barry

    2013-01-01

    Background Mild traumatic brain injury (mTBI) secondary to blast exposure is the most common battlefield injury in Southwest Asia. There has been little prospective work in the combat setting to test the efficacy of new countermeasures. The goal of this study was to compare the efficacy of N-acetyl cysteine (NAC) versus placebo on the symptoms associated with blast exposure mTBI in a combat setting. Methods This study was a randomized double blind, placebo-controlled study that was conducted on active duty service members at a forward deployed field hospital in Iraq. All symptomatic U.S. service members who were exposed to significant ordnance blast and who met the criteria for mTBI were offered participation in the study and 81 individuals agreed to participate. Individuals underwent a baseline evaluation and then were randomly assigned to receive either N-acetyl cysteine (NAC) or placebo for seven days. Each subject was re-evaluated at 3 and 7 days. Outcome measures were the presence of the following sequelae of mTBI: dizziness, hearing loss, headache, memory loss, sleep disturbances, and neurocognitive dysfunction. The resolution of these symptoms seven days after the blast exposure was the main outcome measure in this study. Logistic regression on the outcome of ‘no day 7 symptoms’ indicated that NAC treatment was significantly better than placebo (OR = 3.6, p = 0.006). Secondary analysis revealed subjects receiving NAC within 24 hours of blast had an 86% chance of symptom resolution with no reported side effects versus 42% for those seen early who received placebo. Conclusion This study, conducted in an active theatre of war, demonstrates that NAC, a safe pharmaceutical countermeasure, has beneficial effects on the severity and resolution of sequelae of blast induced mTBI. This is the first demonstration of an effective short term countermeasure for mTBI. Further work on long term outcomes and the potential use of NAC in civilian mTBI is warranted

  16. The tep1 gene of Sinorhizobium meliloti coding for a putative transmembrane efflux protein and N-acetyl glucosamine affect nod gene expression and nodulation of alfalfa plants.

    PubMed

    van Dillewijn, Pieter; Sanjuán, Juan; Olivares, José; Soto, María José

    2009-01-27

    Soil bacteria collectively known as Rhizobium, characterized by their ability to establish beneficial symbiosis with legumes, share several common characteristics with pathogenic bacteria when infecting the host plant. Recently, it was demonstrated that a fadD mutant of Sinorhizobium meliloti is altered in the control of swarming, a type of co-ordinated movement previously associated with pathogenicity, and is also impaired in nodulation efficiency on alfalfa roots. In the phytopathogen Xanthomonas campestris, a fadD homolog (rpfB) forms part of a cluster of genes involved in the regulation of pathogenicity factors. In this work, we have investigated the role in swarming and symbiosis of SMc02161, a S. meliloti fadD-linked gene. The SMc02161 locus in S. meliloti shows similarities with members of the Major Facilitator Superfamily (MFS) of transporters. A S. meliloti null-mutant shows increased sensitivity to chloramphenicol. This indication led us to rename the locus tep1 for transmembrane efflux protein. The lack of tep1 does not affect the appearance of swarming motility. Interestingly, nodule formation efficiency on alfalfa plants is improved in the tep1 mutant during the first days of the interaction though nod gene expression is lower than in the wild type strain. Curiously, a nodC mutation or the addition of N-acetyl glucosamine to the wild type strain lead to similar reductions in nod gene expression as in the tep1 mutant. Moreover, aminosugar precursors of Nod factors inhibit nodulation. tep1 putatively encodes a transmembrane protein which can confer chloramphenicol resistance in S. meliloti by expelling the antibiotic outside the bacteria. The improved nodulation of alfalfa but reduced nod gene expression observed in the tep1 mutant suggests that Tep1 transports compounds which influence nodulation. In contrast to Bradyrhizobium japonicum, we show that in S. meliloti there is no feedback regulation of nodulation genes. Moreover, the Nod factor precursor

  17. Oxyhalogen-sulfur chemistry: kinetics and mechanism of oxidation of N-acetyl homocysteine thiolactone by acidified bromate and aqueous bromine.

    PubMed

    Mbiya, Wilbes; Choi, Boyoung; Martincigh, Bice S; Morakinyo, Moshood K; Simoyi, Reuben H

    2013-12-12

    N-acetyl homocysteine thiolactone (NAHT), medically known as citiolone, can be used as a mucolytic agent and for the treatment of certain hepatic disorders. We have studied the kinetics and mechanisms of its oxidation by acidic bromate and aqueous bromine. In acidic bromate conditions the reaction is characterized by a very short induction period followed by a sudden and rapid formation of bromine and N-acetyl homocysteine sulfonic acid. The stoichiometry of the bromate-NAHT reaction was deduced to be: BrO3(-) + H2O + CH3CONHCHCH2CH2SCO → CH3CONHCHCH2CH2(SO3H)COOH + Br(-) (S1) while in excess bromate it was deduced to be: 6BrO3(-) + 5CH3CONHCHCH2CH2SCO + 6H(+) → 3Br2 + 5CH3CONHCHCH2CH2(SO3H)COOH + 2H2O (S2). For the reaction of NAHT with bromine, a 3:1 stoichiometric ratio of bromine to NAHT was obtained: 3Br2 + CH3CONHCHCH2CH2SCO + 4H2O → 6Br(-) + CH3CONHCHCH2CH2(SO3H)COOH + 6H(+) (S3). Oxidation occurred only on the sulfur center where it was oxidized to the sulfonic acid. No sulfate formation was observed. The mechanism involved an initial oxidation to a relatively stable sulfoxide without ring-opening. Further oxidation of the sulfoxide involved two pathways: one which involved intermediate formation of an unstable sulfone and the other involves ring-opening coupled with oxidation through to the sulfonic acid. There was oligooscillatory production of aqueous bromine. Bromide produced in S1 reacts with excess bromate to produce aqueous bromine. The special stability associated with the sulfoxide allowed it to coexist with aqueous bromine since its further oxidation to the sulfone was not as facile. The direct reaction of aqueous bromine with NAHT was fast with an estimated lower limit bimolecular rate constant of 2.94 ± 0.03 × 10(2) M(-1) s(-1).

  18. O-GlcNAc-selective-N-acetyl-beta-D-glucosaminidase activity and mRNA expression in muscle is related to glucosamine-induced insulin resistance.

    PubMed

    Durán-Reyes, Genoveva; Pascoe-Lira, Dalila; García-Macedo, Rebeca; Medina-Navarro, Rafael; Rosales-Torres, Ana María; Vergara-Onofre, Marcela; Foyo-Niembro, Enrique; Gutiérrez-Rodríguez, Margarita Eugenia; García-Gutiérrez, María Trinidad Adriana; Valladares-Salgado, Adán; Kumate, Jesús; Cruz, Miguel

    2010-01-01

    Glucosamine (GlcN)-induced insulin resistance is associated with an increase in O-linked-N-acetylglucosaminylated modified proteins (O-GlcNAcylated proteins). The role played by O-GlcNAc-selective-N-acetyl-beta-D-glucosaminidase (O-GlcNAcase), which removes O-N-acetyl-glucosamine residues from O-GlcNAcylated proteins, has not yet been demonstrated. We investigated whether GlcN-induced whole-body insulin resistance is related to tissue O-GlcNAcase activity and mRNA expression. GlcN (30 mumol/kg/min) or physiological saline (control) was intravenously infused into Sprague-Dawley rats for 2 h. After GlcN treatment, rats were subjected to the following: intravenous glucose tolerance test, insulin tolerance test or removal of the liver, muscle and pancreas. GlcN was found to provoke hyperglycemia compared to control (8.6 +/- 0.41 vs. 4.82 +/- 0.17 mM, p < 0.001). The insulin resistance index (HOMA-IR) increased (15.76 +/- 1.47 vs. 10.14 +/- 1.41, p < 0.001) and the beta-cell function index (HOMA-beta) diminished (182.69 +/- 22.37 vs. 592.01 +/- 103, p < 0.001). Liver glucose concentration was higher in the GlcN group than in the control group (0.37 +/- 0.04 vs. 0.24 +/- 0.038 mmol/g dry weight, p < 0.001). Insulin release index (insulin/glucose) was less in the GlcN group than in the control (2.2 +/- 0.1 vs. 8 +/- 0.8 at 120 min, p < 0.001). In the GlcN group, muscle O-GlcNAcase activity diminished (0.28 +/- 0.019 vs. 0.36 +/- 0.018 nmol of p-nitrophenyl/mg protein/min, p < 0.001), and K(m) increased (1.51 +/- 0.11 vs. 1.12 +/- 0.1 mM, p < 0.001) compared to the control. In the GlcN group, O-GlcNAcase activity/mRNA expression was altered (0.6 +/- 0.07 vs. 1 +/- 0.09 of control, p < 0.05). In conclusion, O-GlcNAcase activity is posttranslationally inhibited during GlcN-induced insulin resistance. Copyright (c) 2010 S. Karger AG, Basel.

  19. The tep1 gene of Sinorhizobium meliloti coding for a putative transmembrane efflux protein and N-acetyl glucosamine affect nod gene expression and nodulation of alfalfa plants

    PubMed Central

    2009-01-01

    Background Soil bacteria collectively known as Rhizobium, characterized by their ability to establish beneficial symbiosis with legumes, share several common characteristics with pathogenic bacteria when infecting the host plant. Recently, it was demonstrated that a fadD mutant of Sinorhizobium meliloti is altered in the control of swarming, a type of co-ordinated movement previously associated with pathogenicity, and is also impaired in nodulation efficiency on alfalfa roots. In the phytopathogen Xanthomonas campestris, a fadD homolog (rpfB) forms part of a cluster of genes involved in the regulation of pathogenicity factors. In this work, we have investigated the role in swarming and symbiosis of SMc02161, a S. meliloti fadD-linked gene. Results The SMc02161 locus in S. meliloti shows similarities with members of the Major Facilitator Superfamily (MFS) of transporters. A S. meliloti null-mutant shows increased sensitivity to chloramphenicol. This indication led us to rename the locus tep1 for transmembrane efflux protein. The lack of tep1 does not affect the appearance of swarming motility. Interestingly, nodule formation efficiency on alfalfa plants is improved in the tep1 mutant during the first days of the interaction though nod gene expression is lower than in the wild type strain. Curiously, a nodC mutation or the addition of N-acetyl glucosamine to the wild type strain lead to similar reductions in nod gene expression as in the tep1 mutant. Moreover, aminosugar precursors of Nod factors inhibit nodulation. Conclusion tep1 putatively encodes a transmembrane protein which can confer chloramphenicol resistance in S. meliloti by expelling the antibiotic outside the bacteria. The improved nodulation of alfalfa but reduced nod gene expression observed in the tep1 mutant suggests that Tep1 transports compounds which influence nodulation. In contrast to Bradyrhizobium japonicum, we show that in S. meliloti there is no feedback regulation of nodulation genes

  20. Aspartate release from rat hippocampal synaptosomes.

    PubMed

    Bradford, S E; Nadler, J V

    2004-01-01

    Certain excitatory pathways in the rat hippocampus can release aspartate along with glutamate. This study utilized rat hippocampal synaptosomes to characterize the mechanism of aspartate release and to compare it with glutamate release. Releases of aspartate and glutamate from the same tissue samples were quantitated simultaneously. Both amino acids were released by 25 mM K(+), 300 microM 4-aminopyridine (4-AP) and 0.5 and 1 microM ionomycin in a predominantly Ca(2+)-dependent manner. For a roughly equivalent quantity of glutamate released, aspartate release was significantly greater during exposure to elevated [K(+)] than to 4-AP and during exposure to 0.5 than to 1 microM ionomycin. Aspartate release was inefficiently coupled to P/Q-type voltage-dependent Ca(2+) channels and was reduced by KB-R7943, an inhibitor of reversed Na(+)/Ca(2+) exchange. In contrast, glutamate release depended primarily on Ca(2+) influx through P/Q-type channels and was not significantly affected by KB-R7943. Pretreatment of the synaptosomes with tetanus toxin and botulinum neurotoxins C and F reduced glutamate release, but not aspartate release. Aspartate release was also resistant to bafilomycin A(1), an inhibitor of vacuolar H(+)-ATPase, whereas glutamate release was markedly reduced. (+/-) -Threo-3-methylglutamate, a non-transportable competitive inhibitor of excitatory amino acid transport, did not reduce aspartate release. Niflumic acid, a blocker of Ca(2+)-dependent anion channels, did not alter the release of either amino acid. Exogenous aspartate and aspartate recently synthesized from glutamate accessed the releasable pool of aspartate as readily as exogenous glutamate and glutamate recently synthesized from aspartate accessed the releasable glutamate pool. These results are compatible with release of aspartate from either a vesicular pool by a "non-classical" form of exocytosis or directly from the cytoplasm by an as-yet-undescribed Ca(2+)-dependent mechanism. In either case

  1. Overview of pepsin-like aspartic peptidases.

    PubMed

    Dunn, B M

    2001-11-01

    The aspartic peptidase family of enzymes has been implicated in a variety of disease states, from stomach ulcers, to breast cancer, and even Alzheimer's Disease. This unit describes the major characteristics of the aspartic peptidases, including mechanism of action, subcellular and tissue localization, and biological substrate specificity.

  2. Effects of N-acetyl-L-cysteine on redox status and markers of renal function in mice inoculated with Bothrops jararaca and Crotalus durissus terrificus venoms.

    PubMed

    Barone, Juliana Marton; Frezzatti, Rodrigo; Silveira, Paulo Flavio

    2014-03-01

    Renal dysfunction is an important aggravating factor in accidents caused by Crotalus durissus terrificus (Cdt) and Bothrops jararaca (Bj) bites. N-acetyl-l-cysteine (NAC) is well known as a nephroprotective antioxidant with low toxicity. The present study investigated the effects of NAC on redox status and markers of renal function in mice that received vehicle (controls) or venoms (v) of Cdt and Bj. In controls NAC promoted hypercreatinemia, hypouremia, hyperosmolality with decreased urea in urine, hyperproteinuria, decreased protein and increased dipeptidyl peptidase IV (DPPIV) in membrane-bound fraction (MF) from renal cortex (RC) and medulla (RM). NAC ameliorated or normalized altered creatinuria, proteinemia and aminopeptidase (AP) acid in MF, AP basic (APB) in soluble fraction (SF), and neutral AP in SF and MF from RC and RM in vBj envenomation. NAC ameliorated or normalized altered neutral AP in SF from RC and RM, and DPPIV and protein in MF from RC in vCdt envenomation. NAC ameliorated or restored renal redox status respectively in vCdt and vBj, and normalized uricemia in both envenomations. These data are promising perspectives that recommend the clinical evaluation of NAC as potential coadjuvant in the anti venom serotherapy for accidents with these snake's genera. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Modulation of liver L-γ-glutamyl-L-cysteinylglycine homeostasis by N-acetyl-glucosamine-thiazolidine-4(R)-carboxylic acid in mice.

    PubMed

    Liu, Ji; Cai, Wendi; Liu, Wanshun; Han, Baoqin; Chang, Jing; Yang, Yan

    2012-04-01

    The properties of modulating liver L-γ-glutamyl-L-cysteinylglycine (GSH) homeostasis by thiazolidine derivative N-acetyl-glucosamine-thiazolidine-4(R)-carboxylic acid (GlcNAcCys) and the underlying mechanisms were investigated in L-buthionine-[S,R]-sulfoximine (BSO)-induced mice liver GSH depletion model. The data show that BSO (6 mmol/kg body weight; intraperitoneally) significantly decreased liver total sulfhydryl and GSH concentrations when compared with control. When mice were treated with different doses of GlcNAcCys (200, 400, 900 mg/kg body weight; intraperitoneally, respectively), total sulfhydryl and GSH concentrations were significantly increased when measured 6 hours after treatment. The activities of GSH-associated enzymes were also measured. Liver glutathione S-transferase (GST) activities were significantly decreased by BSO compared with the control, and GlcNAcCys significantly increased GST activity. Moreover, reverse-transcriptase polymerase chain reaction data indicated that GlcNAcCys could significantly induce glutamylcysteine ligase catalytic subunit c mRNA transcription. The mRNA levels of transcription factors c-jun and c-fos were increased by BSO administration but were decreased back to normal after the administration of GlcNAcCys. In a conclusion, GlcNAcCys can modulate liver GSH homeostasis, which may be related to its ability to induce glutamylcysteine ligase catalytic subunit transcription. GlcNAcCys has potential hepatoprotective properties by increasing GSH content, increasing GST activity.

  4. Prevention of acetaminophen (APAP)-induced hepatotoxicity by leflunomide via inhibition of APAP biotransformation to N-acetyl-p-benzoquinone imine.

    PubMed

    Tan, Su Ching; New, Lee Sun; Chan, Eric C Y

    2008-08-28

    Acetaminophen (APAP) is safe at therapeutic levels but causes liver injury via N-acetyl-p-benzoquinone imine (NAPQI)-induced oxidative stress when overdose. Recent studies indicated that mitochondrial permeability transition (mPT) plays a key role in APAP-induced toxicity and leflunomide (LEF) protects against the toxicity through inhibition of c-jun NH2-terminal protein kinase (JNK)-mediated pathway of mPT. It is not clearly understood if LEF also exerts its protective effect through inhibition of APAP bioactivation to the toxic NAPQI. The present work was undertaken to study the effect of LEF on the bioactivation of APAP to NAPQI. Mechanism-based inhibition incubations performed in mouse and human liver microsomes (MLM and HLM) indicated that inhibition of APAP bioactivation to NAPQI was observed in MLM but not in HLM. Furthermore, LEF but not its active metabolite, A77-1726, was shown to be the main inhibitor. When APAP and LEF were incubated with human recombinant P450 enzymes, CYP1A2 was found to be the isozyme responsible for the inhibition of APAP bioactivation. Species variation in CYP1A2 enzymes probably accounted for the different observations in our MLM and HLM studies. We concluded that inhibition of NAPQI formation is not a probable pathway that LEF protects APAP-induced hepatotoxicity in human.

  5. Induction of cytokines and ICAM-1 by proinflammatory cytokines in primary rheumatoid synovial fibroblasts and inhibition by N-acetyl-L-cysteine and aspirin.

    PubMed

    Sakurada, S; Kato, T; Okamoto, T

    1996-10-01

    The role of transcription factor NF-kappa B in the induction of cytokines and ICAM-1 upon stimulation with proinflammatory cytokines, IL-1 and tumor necrosis factor (TNF)-alpha was investigated in primary synovial fibroblasts obtained from patients with rheumatoid arthritis (RA). Nuclear translocation of NF-kappa B was demonstrated after 30 min of treatment with IL-1 or TNF-alpha. Thereafter, the production of several cytokines including granulocyte macrophage colony stimulating factor, IL-6 and IL-8, that are known to be abundantly produced in the synovial cavity of RA patients, was greatly augmented. Similarly, cell surface expression of ICAM-1 was induced by the IL-1 or TNF-alpha treatment. Since expression of these genes is induced in rheumatoid synovial tissue, this experimental system is considered to represent the in vivo situation of RA pathophysiology. Using this cell culture system we attempted to modulate the intracellular signaling cascade for NF-kappa B activation and examined the effects of N-acetyl-L-cysteine (NAC) and acetylsalicylic acid (aspirin), which were previously reported to inhibit NF-kappa B activation. Pretreatment of the primary synovial fibroblasts with NAC inhibited nuclear translocation of NF-kappa B. Subsequently, the induction of these cytokines and ICAM-1 was considerably suppressed. On the other hand, pretreatment with aspirin blocked these phenomena only partially. These observations indicate the pivotal role of NF-kappa B in RA pathogenesis thus highlighting the possibility of a novel therapeutic strategy.

  6. Synthesis and Characterization of the Novel Nitric Oxide (NO) Donating Compound, S-nitroso-N-acetyl-D-penicillamine Derivatized Cyclam (SNAP-Cyclam).

    PubMed

    McCarthy, Connor W; Goldman, Jeremy; Frost, Megan C

    2016-03-09

    Nitric oxide (NO) has been heavily studied over the past two decades due to its multitude of physiological functions and its potential therapeutic promise. Of major interest is the desire to fabricate or coat implanted devices with an NO releasing material that will impart the appropriate dose and duration of NO release to positively mediate the biological response to the medical device, thereby improving its safety and efficacy. To date, this goal has not yet been achieved, despite very promising early research. Herein, we describe the synthesis and NO release properties of a novel NO donor which covalently links the S-nitrosothiol, S-nitroso-N-acetyl-D-penicillamine (SNAP), to the macrocycle, cyclam (SNAP-cyclam). This compound can then be blended into a wide variety of polymer matrices, imparting NO release to the polymer system. This release can be initiated and controlled by transition metal catalysis, thermal degradation or photolytic release of NO from the composite NO-releasing material. SNAP-cyclam is capable of releasing physiologically relevant levels of NO for up to 3 months in vitro when blended into poly(l-lactic acid) thin films.

  7. Identification of functionally important cysteine residues of the human renin-binding protein as the enzyme N-acetyl-D-glucosamine 2-epimerase.

    PubMed

    Takahashi, S; Takahashi, K; Kaneko, T; Ogasawara, H; Shindo, S; Saito, K; Kawamura, Y

    2001-04-01

    Renin-binding protein (RnBP) is an endogenous renin inhibitor originally isolated from porcine kidney. It was recently identified as the enzyme N-acetyl-D-glucosamine (GlcNAc) 2-epimerase [Takahashi, S. et al. (1999) J. Biochem. 125, 348-353] and its active site residue was determined to be cysteine 380 by site-directed mutagenesis [Takahashi, S. et al. (1999) J. Biochem. 126, 639-642]. To further investigate the relationship between structure and function of recombinant human (rh) RnBP as a GlcNAc 2-epimerase, we have constructed several C-terminal deletion and multi-cysteine/serine mutants of rhGlcNAc 2-epimerase and expressed them in Escherichia coli cells. The expression was detected by Western blotting using anti-rhRnBP antiserum. The C-terminal deletion mutant, Delta400-417, had approximately 50% activity relative to the wild-type enzyme, but other C-terminal deletion mutants, Delta380-417, Delta386-417, and Delta390-417, had no enzymatic activity. Mutational analysis of multi-cysteine/serine mutants revealed that cysteines 41 and 390 were critical for the activity or stabilization of the enzyme, while cysteine residues in the middle of the enzyme, cysteines 125, 210, 239, and 302, had no essential function in relation to the activity.

  8. Antioxidant N-acetyl-L-cysteine ameliorates symptoms of premature aging associated with the deficiency of the circadian protein BMAL1

    PubMed Central

    Kondratov, Roman V.; Vykhovanets, Olena; Kondratova, Anna A.; Antoch, Marina P.

    2009-01-01

    Deficiency of the circadian clock protein BMAL1 leads to premature aging and increased levels of reactivate oxygen species in several tissues of mice. In order to investigate the role of oxidative stress in accelerated aging and development of age-related pathologies, we continuously administered the antioxidant N-acetyl-L-cysteine toBmal1-deficient mice through their entire lifespan by supplementing drinking water. We found that the life long treatment with antioxidant significantly increased average and maximal lifespan and reduced the rate of age-dependent weight loss and development of cataracts. At the same time, it had no effect on time of onset and severity of other age-related pathologies characteristic of Bmal1-/- mice, such as joint ossification, reduced hair regrowth and sarcopenia. We conclude that chronic oxidative stress affects longevity and contributes to the development of at least some age-associated pathology, although ROS-independent mechanisms may also play a role. Our bioinformatics analysis identified the presence of a conservative E box element in the promoter regions of several genes encoding major antioxidant enzymes. We speculate that BMAL1 controls antioxidant defense by regulating the expression of major antioxidant enzymes. PMID:20157581

  9. Transport of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine, a metabolite of trichloroethylene, by mouse multidrug resistance associated protein 2 (Mrp2).

    PubMed

    Tsirulnikov, Kirill; Abuladze, Natalia; Koag, Myong-Chul; Newman, Debra; Scholz, Karoline; Bondar, Galyna; Zhu, Quansheng; Avliyakulov, Nuraly K; Dekant, Wolfgang; Faull, Kym; Kurtz, Ira; Pushkin, Alexander

    2010-04-15

    N-acetyl-S-(1,2-dichlorovinyl)-l-cysteine (Ac-DCVC) and S-(1,2-dichlorovinyl)-l-cysteine (DCVC) are the glutathione conjugation pathway metabolites of a common industrial contaminant and potent nephrotoxicant trichloroethylene (TCE). Ac-DCVC and DCVC are accumulated in the renal proximal tubule where they may be secreted into the urine by an unknown apical transporter(s). In this study, we explored the hypothesis that the apical transport of Ac-DCVC and/or DCVC may be mediated by the multidrug resistance associated protein 2 (Mrp2, ABCC2), which is known to mediate proximal tubular apical ATP-dependent transport of glutathione and numerous xenobiotics and endogenous substances conjugated with glutathione. Transport experiments using membrane vesicles prepared from mouse proximal tubule derived cells expressing mouse Mrp2 utilizing ATPase assay and direct measurements of Ac-DCVC/DCVC using liquid chromatography/tandem mass-spectrometry (LC/MS/MS) demonstrated that mouse Mrp2 mediates ATP-dependent transport of Ac-DCVC. Expression of mouse Mrp2 antisense mRNA significantly inhibited the vectorial basolateral to apical transport of Ac-DCVC but not DCVC in mouse proximal tubule derived cells endogenously expressing mouse Mrp2. The results suggest that Mrp2 may be involved in the renal secretion of Ac-DCVC.

  10. Transport of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine, a metabolite of trichloroethylene, by mouse multidrug resistance associated protein 2 (Mrp2)

    PubMed Central

    Tsirulnikov, Kirill; Abuladze, Natalia; Koag, Myong-Chul; Newman, Debra; Scholz, Karoline; Bondar, Galyna; Zhu, Quansheng; Avliyakulov, Nuraly K.; Dekant, Wolfgang; Faull, Kym; Kurtz, Ira; Pushkin, Alexander

    2010-01-01

    N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (Ac-DCVC) and S-(1,2-dichlorovinyl)-L-cysteine (DCVC) are the glutathione conjugation pathway metabolites of a common industrial contaminant and potent nephrotoxicant trichloroethylene (TCE). Ac-DCVC and DCVC are accumulated in the renal proximal tubule where they may be secreted into the urine by an unknown apical transporter(s). In this study we explored the hypothesis that the apical transport of Ac-DCVC and/or DCVC may be mediated by the multidrug resistance associated protein 2 (Mrp2, ABCC2), which is known to mediate proximal tubular apical ATP-dependent transport of glutathione and numerous xenobiotics and endogenous substances conjugated with glutathione. Transport experiments using membrane vesicles prepared from mouse proximal tubule derived cells expressing mouse Mrp2 utilizing ATPase assay and direct measurements of Ac-DCVC/DCVC using liquid chromatography/tandem mass-spectrometry (LC/MS/MS) demonstrated that mouse Mrp2 mediates ATP-dependent transport of Ac-DCVC. Expression of mouse Mrp2 antisense mRNA significantly inhibited the vectorial basolateral to apical transport of Ac-DCVC but not DCVC in mouse proximal tubule derived cells endogenously expressing mouse Mrp2. The results suggest that Mrp2 may be involved in the renal secretion of Ac-DCVC. PMID:20060011

  11. Restoring the impaired cardiac calcium homeostasis and cardiac function in iron overload rats by the combined deferiprone and N-acetyl cysteine

    PubMed Central

    Wongjaikam, Suwakon; Kumfu, Sirinart; Khamseekaew, Juthamas; Chattipakorn, Siriporn C.; Chattipakorn, Nipon

    2017-01-01

    Intracellular calcium [Ca2+]i dysregulation plays an important role in the pathophysiology of iron overload cardiomyopathy. Although either iron chelators or antioxidants provide cardioprotection, a comparison of the efficacy of deferoxamine (DFO), deferiprone (DFP), deferasirox (DFX), N-acetyl cysteine (NAC) or a combination of DFP plus NAC on cardiac [Ca2+]i homeostasis in chronic iron overload has never been investigated. Male Wistar rats were fed with either a normal diet or a high iron (HFe) diet for 4 months. At 2 months, HFe rats were divided into 6 groups and treated with either a vehicle, DFO (25 mg/kg/day), DFP (75 mg/kg/day), DFX (20 mg/kg/day), NAC (100 mg/kg/day), or combined DFP plus NAC. At 4 months, the number of cardiac T-type calcium channels was increased, whereas cardiac sarcoplasmic-endoplasmic reticulum Ca2+ ATPase (SERCA) was decreased, leading to cardiac iron overload and impaired cardiac [Ca2+]i homeostasis. All pharmacological interventions restored SERCA levels. Although DFO, DFP, DFX or NAC alone shared similar efficacy in improving cardiac [Ca2+]i homeostasis, only DFP + NAC restored cardiac [Ca2+]i homeostasis, leading to restoring left ventricular function in the HFe-fed rats. Thus, the combined DFP + NAC was more effective than any monotherapy in restoring cardiac [Ca2+]i homeostasis, leading to restored myocardial contractility in iron-overloaded rats. PMID:28287621

  12. Comparison of the effects of N-acetyl-cysteine and ginseng in prevention of noise induced hearing loss in male textile workers.

    PubMed

    Doosti, Afsaneh; Lotfi, Yones; Moossavi, Abdollah; Bakhshi, Enayatollah; Talasaz, Azita Hajhossein; Hoorzad, Ahmad

    2014-01-01

    Previous studies revealed the role of antioxidant agents in prevention of noise induced hearing loss (NIHL). The aim of this study was to compare the protective effect of N-acetyl-cysteine (NAC) and ginseng on protection of NIHL in textile workers exposed to continuous noise in daily working. In this study, 48 participants were randomly allocated to three groups; Group I received NAC 1200 mg/day, Group II received ginseng 200 mg/day, and Group III (control group) received no supplement. Pure tone audiometry and high frequency audiometry were performed preshift before and after 14 days (on day 15). Linear regression analysis results showed reduced noise-induced temporary threshold shift (TTS) for NAC and ginseng groups at 4, 6 and 16 kHz (P < 0.001) in both ears. Furthermore, the protective effects were more prominent in NAC than ginseng. Our results show that NAC and ginseng can reduce noise induced TTS in workers exposed to occupational noise. Further studies are needed to prove antioxidants benefits in hearing conservation programs.

  13. Enhancing effect of N-acetyl-l-cysteine or 2-mercaptoethanol on the in vitro permeation of 5-fluorouracil or tolnaftate through the human nail plate.

    PubMed

    Kobayashi, Y; Miyamoto, M; Sugibayashi, K; Morimoto, Y

    1998-11-01

    The enhancing effects of various vehicles on the in vitro permeation of a hydrophilic model drug, 5-fluorouracil (5-FU), or a lipophilic model drug, tolnaftate (TN), through human nail plates were investigated using a modified side-by-side diffusion cell. Tip pieces from the 5th finger-nail, clipped from healthy volunteers, were used in this permeation study. The swelling and softening properties of the nail pieces were also measured in each vehicle. The weights and stresses of the nail pieces were dramatically changed after immersion in aqueous solvents containing N-acetyl-L-cysteine (AC) or 2-mercaptoethanol (ME). However, no significant change in the physicochemical properties of the nail pieces was found in the lipophilic vehicles. Thus, the water content in the nail plates absorbed from vehicles may relate to their physicochemical properties. Although keratin-softening agents and new skin permeation enhancers did not significantly promote 5-FU permeation compared with water alone, the flux from solvent systems containing AC or ME was substantially higher. In addition, TN permeation from solvents containing AC or ME could be measured, whereas that from other solvents was undetectable. When the AC concentration was increased, the 5-FU permeation and the nail weight increased and the stress of each nail piece decreased. It is concluded from these experimental results that AC and ME may be useful as enhancers for increasing drug permeation through the human nail plate.

  14. N-acetyl-cysteine prevents age-related hearing loss and the progressive loss of inner hair cells in γ-glutamyl transferase 1 deficient mice.

    PubMed

    Ding, Dalian; Jiang, Haiyan; Chen, Guang-Di; Longo-Guess, Chantal; Muthaiah, Vijaya Prakash Krishnan; Tian, Cong; Sheppard, Adam; Salvi, Richard; Johnson, Kenneth R

    2016-04-01

    Genetic factors combined with oxidative stress are major determinants of age-related hearing loss (ARHL), one of the most prevalent disorders of the elderly. Dwarf grey mice, Ggt1dwg/dwg, are homozygous for a loss of function mutation of the g-glutamyl transferase 1 gene, which encodes an important antioxidant enzyme critical for the resynthesis of glutathione (GSH). Since GSH reduces oxidative damage, we hypothesized that Ggt1dwg/dwg mice would be susceptible to ARHL. Surprisingly, otoacoustic emissions and cochlear microphonic potentials, which reflect cochlear outer hair cell (OHC) function, were largely unaffected in mutant mice, whereas auditory brainstem responses and the compound action potential were grossly abnormal. These functional deficits were associated with an unusual and selective loss of inner hair cells (IHC), but retention of OHC and auditory nerve fibers. Remarkably, hearing deficits and IHC loss were completely prevented by N-acetyl-L-cysteine, which induces de novo synthesis of GSH; however, hearing deficits and IHC loss reappeared when treatment was discontinued. Ggt1dwg/dwg mice represent an important new model for investigating ARHL, therapeutic interventions, and understanding the perceptual and electrophysiological consequences of sensory deprivation caused by the loss of sensory input exclusively from IHC.

  15. Protection from Staphylococcus aureus mastitis associated with poly-N-acetyl β-1,6 glucosamine specific antibody production using biofilm-embedded bacteria

    PubMed Central

    Pérez, M. M.; Prenafeta, A.; Valle, J.; Penadés, J.; Rota, C.; Solano, C.; Marco, J.; Grilló, M.J.; Lasa, I.; Irache, J.M.; Maira-Litran, T.; Jiménez-Barbero, J.; Costa, L.; Pier, G.B.; de Andrés, D.; Amorena, B.

    2010-01-01

    Staphylococcus aureus vaccines based on bacterins surrounded by slime, surface polysaccharides coupled to protein carriers and polysaccharides embedded in liposomes administered together with non-biofilm bacterins confer protection against mastitis. However, it remains unknown whether protective antibodies are directed to slime-associated known exopolysaccharides and could be produced in the absence of bacterin immunizations. Here, a sheep mastitis vaccination study was carried out using bacterins, crude bacterial extracts or a purified exopolysaccharide from biofilm bacteria delivered in different vehicles. This polysaccharide reacted specifically with antibodies to poly-N-acetyl-β-1,6-glucosamine (PNAG) and not with antibodies to other capsular antigens or bacterial components. Following intra-mammary challenge with biofilm-producing bacteria, antibody production against the polysaccharide, milk bacterial counts and mastitis lesions were determined. Bacterins from strong biofilm-producing bacteria triggered the highest production of antibodies to PNAG and conferred the highest protection against infection and mastitis, compared with weak biofilm-producing bacteria and non-cellular inocula. Thus, bacterins from strong biofilm bacteria, rather than purified polysaccharide, are proposed as a cost-efficient vaccination against S. aureus ruminant mastitis. PMID:19428854

  16. The effects of N-acetyl-L-cysteine supplementation on in vitro porcine oocyte maturation and subsequent fertilisation and embryonic development.

    PubMed

    Whitaker, B D; Casey, S J; Taupier, R

    2012-01-01

    The effects of supplementation with 1.5 mM n-acetyl-l-cysteine (NAC) during in vitro oocyte maturation were studied. Oocytes were supplemented with 1.5 mM NAC during maturation for 0 to 24 h, 24 to 48 h, or 0 to 48 h then subjected to IVF and embryo development. Oocytes were evaluated after maturation for intracellular glutathione concentration, superoxide dismutase and glutathione peroxidase activities and DNA fragmentation. Fertilisation and embryonic development success were also evaluated. There was no effect of treatment on intracellular glutathione concentrations, enzyme activities or fertilisation success rates. Supplementing NAC during maturation significantly decreased (P < 0.05) the percentage of oocytes with fragmented DNA compared with no NAC supplementation. Supplementing NAC from 24 to 48 h or 0 to 48 h resulted in a significantly higher (P < 0.05) percentage of oocytes with male pronuclei than for oocytes from the other treatment groups. There was no difference in the percentage of embryos cleaved by 48 h after IVF between treatment groups. Supplementing NAC from 24 to 48 h or 0 to 48 h resulted in a significantly higher (P < 0.05) percentage of embryos reaching the blastocyst stage by 144 h after IVF compared with the other treatment groups. These results indicate that supplementation of the oocyte maturation medium with 1.5 mM NAC, specifically during the last 24 h, improves male pronucleus formation and blastocyst development in pigs.

  17. N-acetyl-L-cysteine pre-treatment protects cryopreserved bovine spermatozoa from reactive oxygen species without compromising the in vitro developmental potential of intracytoplasmic sperm injection embryos.

    PubMed

    Pérez, L; Arias, M E; Sánchez, R; Felmer, R

    2015-12-01

    Excess of reactive oxygen species (ROS) on in vitro embryo production systems negatively affects the quality and developmental potential of embryos, as result of a decreased sperm quality and increased DNA fragmentation. This issue is of major importance in assisted fertilisation procedures such as intracytoplasmic sperm injection (ICSI), because this technique does not allow the natural selection of competent spermatozoa, and therefore, DNA-damaged spermatozoa might be used to fertilise an egg. The aim of this study was to investigate a new strategy to prevent the potential deleterious effect of ROS on cryopreserved bovine spermatozoa. We evaluated the effect of a sperm pre-treatment with different concentrations of N-acetyl-L-cysteine (NAC) on ROS production, viability and DNA fragmentation and assessed the effect of this treatment on the in vitro developmental potential and quality of embryos generated by ICSI. The results show a strong scavenging effect of 1 and 10 mm NAC after exposure of spermatozoa to a ROS inducer, without compromising the viability and DNA integrity. Importantly, in vitro developmental potential and quality of embryos generated by ICSI with spermatozoa treated with NAC were not affected, confirming the feasibility of using this treatment before an ICSI cycle.

  18. The lysosomal N-acetyl-beta-D-glucosaminidase (NAG) isoenzymes in plasma: study of distribution in a general population by a simple routine chromatofocusing procedure.

    PubMed

    Goi, G; Bairati, C; Roggi, C; Maccarini, L; Tettamanti, G; Meloni, C; Lombardo, A

    1993-11-30

    We have adapted for routine analysis a pre-existing method for separating the three major N-acetyl-beta-D-glucosaminidase (NAG) isoenzyme forms--A, B+I1 and I2--by chromatofocusing followed by fluorimetric assay of the enzyme activity. This method combines good resolution, accurate quantification of the different isoenzymes and high reproducibility with an acceptable degree of analytical precision. We have applied it to studying the isoenzyme levels in the plasma of a general population of 417 subjects and have analysed these enzyme activities as functions of age, sex, body mass and declared alcohol consumption. Unlike the levels of unfractionated enzyme, levels of all the isoenzymes were higher in men than in women at all ages except in the 20-29 year group. Isoenzyme I2 showed the greatest sex difference. On the whole, with increasing age, both sexes showed more or less regular increases in plasma levels of all the isoenzymes. We also found significant correlations for the population as a whole with age and with body mass index. The only significant correlation with alcohol consumption was for B+I1 in men.

  19. Simultaneous determination of N-acetyl-p-aminophenol and p-aminophenol with poly(3,4-ethylenedioxythiophene) modified glassy carbon electrode.

    PubMed

    Mehretie, Solomon; Admassie, Shimelis; Hunde, Tadele; Tessema, Merid; Solomon, Theodros

    2011-09-15

    A sensitive and selective method was developed for the determination of N-acetyl-p-aminophenol (APAP) and p-aminophenol (PAP) using poly(3,4-ethylenedioxythiophene) (PEDOT)-modified glassy carbon electrode (GCE). Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical reaction of APAP and PAP at the modified electrode. Both APAP and PAP showed quasireversible redox reactions with formal potentials of 367 mV and 101 mV (vs. Ag/AgCl), respectively, in phosphate buffer solution of pH 7.0. The significant peak potential difference (266 mV) between APAP and PAP enabled the simultaneous determination both species based on differential pulse voltammetry. The voltammetric responses gave linear ranges of 1.0×10(-6)-1.0×10(-4) mol L(-1) and 4.0×10(-6)-3.2×10(-4) mol L(-1), with detection limits of 4.0×10(-7) mol L(-1) and 1.2×10(-6) mol L(-1) for APAP and PAP, respectively. The method was successfully applied for the determination of APAP and PAP in pharmaceutical formulations and biological samples.

  20. Mitochondrial protein adducts formation and mitochondrial dysfunction during N-acetyl-m-aminophenol (AMAP)-induced hepatotoxicity in primary human hepatocytes

    PubMed Central

    Xie, Yuchao; McGill, Mitchell R.; Du, Kuo; Dorko, Kenneth; Kumer, Sean C.; Schmitt, Timothy M.; Ding, Wen-Xing; Jaeschke, Hartmut

    2015-01-01

    3′-Hydroxyacetanilide or N-acetyl-meta-aminophenol (AMAP) is generally regarded as a non-hepatotoxic analog of acetaminophen (APAP). Previous studies demonstrated absence of toxicity after AMAP in mice, hamsters, primary mouse hepatocytes and several cell lines. In contrast, experiments with liver slices suggested that it may be toxic to human hepatocytes; however, the mechanism of toxicity is unclear. To explore this, we treated primary human hepatocytes (PHH) with AMAP or APAP for up to 48 h and measured several parameters to assess metabolism and injury. Although less toxic than APAP, AMAP dose-dependently triggered cell death in PHH as indicated by alanine aminotransferase (ALT) release and propidium iodide (PI) staining. Similar to APAP, AMAP also significantly depleted glutathione (GSH) in PHH and caused mitochondrial damage as indicated by glutamate dehydrogenase (GDH) release and the JC-1 assay. However, unlike APAP, AMAP treatment did not cause relevant c-jun-N-terminal kinase (JNK) activation in the cytosol or phospho-JNK translocation to mitochondria. To compare, AMAP toxicity was assessed in primary mouse hepatocytes (PMH). No cytotoxicity was observed as indicated by the lack of lactate dehydrogenase release and no PI staining. Furthermore, there was no GSH depletion or mitochondrial dysfunction after AMAP treatment in PMH. Immunoblotting for arylated proteins suggested that AMAP treatment caused extensive mitochondrial protein adducts formation in PHH but not in PMH. In conclusion, AMAP is hepatotoxic in PHH and the mechanism involves formation of mitochondrial protein adducts and mitochondrial dysfunction. PMID:26431796

  1. L-cysteine, N-acetyl-L-cysteine, and glutathione protect Xenopus laevis embryos against acrylamide-induced malformations and mortality in the frog embryo teratogenesis assay.

    PubMed

    Rayburn, James R; Friedman, Mendel

    2010-10-27

    Dietary acrylamide is largely derived from heat-induced reactions between the amino group of the free amino acid asparagine and carbonyl groups of glucose and fructose during heat processing (baking, frying) of plant-derived foods such as potato fries and cereals. After consumption, acrylamide is absorbed into the circulation and is then distributed to various organs, where it can react with DNA, neurons, hemoglobin, and essential enzymes. In the present study, we explored the potential of L-cysteine (CySH), N-acetyl-L-cysteine (NAC), reduced glutathione (GSH), and the amino acid glycine (Gly) to protect frog embryos against acrylamide-induced developmental toxicity in the frog embryo teratogenesis assay - Xenopus (FETAX). To test the antiteratogenic potential, based on concentration-response study ranging from 0.07 to 4.22 mM acrylamide in FETAX solution (pH 8.1), we selected concentrations of acrylamide that induced 100% malformations and mortality. At the end of 96 h, we counted survivors and malformed embryos and measured embryo length. The data show that CySH, NAC, and GSH protected the embryos against acrylamide induced malformations and mortality to different degrees. CySH and GSH protected the embryos against both malformations and mortality, whereas NAC protected only against mortality. Gly had no protective effect. Possible mechanisms of the protective effects and the dietary significance of the results of this and related studies for food safety and human health are discussed.

  2. Investigation of the association behaviors between bovine serum albumin and 2-(4-methylphenyl)-3-(N-acetyl)-5-(2,4-dichlorophenoxymethyl)-1,3,4-oxodiazoline.

    PubMed

    Huang, Zhenzhong; Wang, Ruiling; Han, Erwei; Xu, Lifan; Song, Yonghai

    2013-07-01

    The study was designed to examine the interaction between 2-(4-methylphenyl)-3-(N-acetyl)-5-(2,4-dichlorophenoxymethyl)-1,3,4-oxodiazoline (MPNDO) and bovine serum albumin (BSA) under physiological conditions by using fluorescence spectroscopy, ultraviolet absorption spectroscopy, FT-IR spectroscopy and circular dichroism spectroscopy and atomic force microscope. Spectroscopic analysis of the fluorescence emission quenching and ultraviolet absorption revealed that the quenching mechanism of bovine serum albumin by MPNDO was static quenching procedure. The binding constant and binding sites number at different temperatures were measured. The average binding distances between donor (BSA) and acceptor (MPNDO) was estimated to be 1.46 nm (301 K), based on the Föster non-radioactive energy transfer theory. An average size of 3.1 nm had a high proportion and these dots might be ascribed to BSA, some other dots with an average size of 6.6 nm might result from BSA-MPNDO bioconjugates while the average diameter of MPNDO was 1.6 nm, which was reasonable to conclude that one BSA-MPNDO bioconjugates consisted of one BSA and one MPNDO. The thermodynamic parameters, enthalpy change (ΔH), entropy change (ΔS) and free energy change (ΔG) were calculated, which indicated that the action force was mainly van der Waals forces. The data collected through synchronous fluorescence, FT-IR spectroscopy and circular dichroism spectroscopy demonstrated that the conformation of BSA was not affected obviously in the presence of MPNDO.

  3. Hydrothermal conversion of N-acetyl-d-glucosamine to 5-hydroxymethylfurfural using ionic liquid as a recycled catalyst in a water-dimethyl sulfoxide mixture.

    PubMed

    Zang, Hongjun; Yu, Songbai; Yu, Pengfei; Ding, Hongying; Du, Yannan; Yang, Yuchan; Zhang, Yiwen

    2017-04-10

    Here, N-acetyl-d-glucosamine (GlcNAc), the monomer composing the second most abundant biopolymer, chitin, was efficiently converted into 5-hydroxymethylfurfural (5-HMF) using ionic liquid (IL) catalysts in a water/dimethyl sulfoxide (DMSO) mixture solvent. Various reaction parameters, including reaction temperature and time, DMSO/water mass ratios and catalyst dosage were optimized. A series of ILs with different structures were analyzed to explore their impact on GlcNAc conversion. The substrate scope was expanded from GlcNAc to d-glucosamine, chitin, chitosan and monosaccharides, although 5-HMF yields obtained from polymers and other monosaccharides were generally lower than those from GlcNAc. Moreover, the IL N-methylimidazolium hydrogen sulfate ([Hmim][HSO4]) exhibited the best catalyst performance (64.6% yield) when GlcNAc was dehydrated in a DMSO/water mixture at 180 °C for 6 h without the addition of extra catalysts. To summarize, these results could provide knowledge essential to the production of valuable chemicals that are derived from renewable marine resources and benefit biofuel-related applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. N-acetylated Proline–Glycine–Proline induced G-protein dependent chemotaxis of neutrophils is independent of CXCL8 release

    PubMed Central

    Overbeek, Saskia A.; Henricks, Paul A.J.; Srienc, Anja I.; Koelink, Pim J.; de Kruijf, Petra; Lim, Herman D.; Smit, Martine J.; Zaman, Guido J.R.; Garssen, Johan; Nijkamp, Frans P.; Kraneveld, Aletta D.; Folkerts, Gert

    2013-01-01

    Chronic inflammation in lung diseases contributes to lung tissue destruction leading to the formation of chemotactic collagen fragments such as N-acetylated Proline–Glycine–Proline (N-ac-PGP). In this study, we investigated in more detail the mechanism of action of N-ac-PGP in neutrophilic inflammation. N-ac-PGP was chemotactic for human neutrophils via pertussis toxin sensitive G protein-coupled receptors in vitro and directly activated this cell type, which led to cytosolic calcium mobilization and release of CXCL8. Furthermore, using a selective CXCR2 antagonist confirmed that N-ac-PGP-induced neutrophil chemotaxis is mediated through CXCR2 activation. To determine whether N-ac-PGP was solely responsible for the migration and activation of human neutrophils in vitro and not the released CXCL8 upon stimulation with N-ac-PGP, an antibody directed against CXCL8 was used. Performing chemotaxis and calcium influx assays in the presence of this antibody did not alter the effects of N-ac-PGP whereas effects of CXCL8 were attenuated. These experiments indicate that N-ac-PGP, in addition to the direct induction of chemotaxis, also directly activates neutrophils to release CXCL8. In vivo, this may lead in the long term to a self-maintaining situation enhanced by both N-ac-PGP and CXCL8, leading to a further increase in neutrophil infiltration and chronic inflammation. PMID:21458443

  5. N-acetylated Proline-Glycine-Proline induced G-protein dependent chemotaxis of neutrophils is independent of CXCL8 release.

    PubMed

    Overbeek, Saskia A; Henricks, Paul A J; Srienc, Anja I; Koelink, Pim J; de Kruijf, Petra; Lim, Herman D; Smit, Martine J; Zaman, Guido J R; Garssen, Johan; Nijkamp, Frans P; Kraneveld, Aletta D; Folkerts, Gert

    2011-10-15

    Chronic inflammation in lung diseases contributes to lung tissue destruction leading to the formation of chemotactic collagen fragments such as N-acetylated Proline-Glycine-Proline (N-ac-PGP). In this study, we investigated in more detail the mechanism of action of N-ac-PGP in neutrophilic inflammation. N-ac-PGP was chemotactic for human neutrophils via pertussis toxin sensitive G protein-coupled receptors in vitro and directly activated this cell type, which led to cytosolic calcium mobilization and release of CXCL8. Furthermore, using a selective CXCR2 antagonist confirmed that N-ac-PGP-induced neutrophil chemotaxis is mediated through CXCR2 activation. To determine whether N-ac-PGP was solely responsible for the migration and activation of human neutrophils in vitro and not the released CXCL8 upon stimulation with N-ac-PGP, an antibody directed against CXCL8 was used. Performing chemotaxis and calcium influx assays in the presence of this antibody did not alter the effects of N-ac-PGP whereas effects of CXCL8 were attenuated. These experiments indicate that N-ac-PGP, in addition to the direct induction of chemotaxis, also directly activates neutrophils to release CXCL8. In vivo, this may lead in the long term to a self-maintaining situation enhanced by both N-ac-PGP and CXCL8, leading to a further increase in neutrophil infiltration and chronic inflammation. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 1 can support immune responses toward tumors overexpressing ganglioside D3 in mice.

    PubMed

    Eby, Jonathan M; Barse, Levi; Henning, Steven W; Rabelink, Martijn J W E; Klarquist, Jared; Gilbert, Emily R; Hammer, Adam M; Fernandez, Manuel F; Yung, Nathan; Khan, Safia; Miller, Hannah G; Kessler, Edward R; Garrett-Mayer, Elizabeth; Dilling, Daniel F; Hoeben, Rob C; Le Poole, I Caroline

    2017-01-01

    An immunotherapeutic strategy is discussed supporting anti-tumor activity toward malignancies overexpressing ganglioside D3. GD3 can be targeted by NKT cells when derived moieties are presented in the context of CD1d. NKT cells can support anti-tumor responses by secreting inflammatory cytokines and through cytotoxicity toward CD1d(+)GD3(+) tumors. To overexpress GD3, we generated expression vector DNA and an adenoviral vector encoding the enzyme responsible for generating GD3 from its ubiquitous precursor GM3. We show that DNA encoding α-N-acetyl-neuraminide α-2,8-sialyltransferase 1 (SIAT8) introduced by gene gun vaccination in vivo leads to overexpression of GD3 and delays tumor growth. Delayed tumor growth is dependent on CD1d expression by host immune cells, as shown in experiments engaging CD1d knockout mice. A trend toward greater NKT cell populations among tumor-infiltrating lymphocytes is associated with SIAT8 vaccination. A single adenoviral vaccination introduces anti-tumor activity similarly to repeated vaccination with naked DNA. Here, greater NKT tumor infiltrates were accompanied by marked overexpression of IL-17 in the tumor, later switching to IL-4. Our results suggest that a single intramuscular adenoviral vaccination introduces overexpression of GD3 by antigen-presenting cells at the injection site, recruiting NKT cells that provide an inflammatory anti-tumor environment. We propose adenoviral SIAT8 (AdV-SIAT8) can slow the growth of GD3 expressing tumors in patients.

  7. Reengineering of the feedback-inhibition enzyme N-acetyl-L-glutamate kinase to enhance L-arginine production in Corynebacterium crenatum.

    PubMed

    Zhang, Jingjing; Xu, Meijuan; Ge, Xiaoxun; Zhang, Xian; Yang, Taowei; Xu, Zhenghong; Rao, Zhiming

    2017-02-01

    N-acetyl-L-glutamate kinase (NAGK) catalyzes the second step of L-arginine biosynthesis and is inhibited by L-arginine in Corynebacterium crenatum. To ascertain the basis for the arginine sensitivity of CcNAGK, residue E19 which located at the entrance of the Arginine-ring was subjected to site-saturated mutagenesis and we successfully illustrated the inhibition-resistant mechanism. Typically, the E19Y mutant displayed the greatest deregulation of L-arginine feedback inhibition. An equally important strategy is to improve the catalytic activity and thermostability of CcNAGK. For further strain improvement, we used site-directed mutagenesis to identify mutations that improve CcNAGK. Results identified variants I74V, F91H and K234T display higher specific activity and thermostability. The L-arginine yield and productivity of the recombinant strain C. crenatum SYPA-EH3 (which possesses a combination of all four mutant sites, E19Y/I74V/F91H/K234T) reached 61.2 and 0.638 g/L/h, respectively, after 96 h in 5 L bioreactor fermentation, an increase of approximately 41.8% compared with the initial strain.

  8. Disruption of intermolecular disulfide bonds in PDGF-BB dimers by N-acetyl-L-cysteine does not prevent PDGF signaling in cultured hepatic stellate cells

    SciTech Connect

    Borkham-Kamphorst, Erawan; Meurer, Steffen K.; Gressner, Axel M.; Weiskirchen, Ralf . E-mail: rweiskirchen@ukaachen.de

    2005-12-30

    Oxidative stress is important in the pathogenesis of liver fibrosis through its induction of hepatic stellate cell (HSC) proliferation and enhancement of collagen synthesis. Reactive oxygen species have been found to be essential second messengers in the signaling of both major fibrotic growth factors, platelet-derived growth factor (PDGF) and transforming growth factor-{beta} (TGF-{beta}), in cultured HSC and liver fibrosis. The non-toxic aminothiol N-acetyl-L-cysteine (NAC) inhibits cellular activation and attenuates experimental fibrosis in liver. Prior reports show that NAC is capable of reducing the effects of TGF-{beta} in biological systems, in cultured endothelial cells, and HSC through its direct reducing activity upon TGF-{beta} molecules. We here analyzed the effects of NAC on PDGF integrity, receptor binding, and downstream signaling in culture-activated HSC. We found that NAC dose-dependently induces disintegration of PDGF in vitro. However, even high doses (>20 mM) were not sufficient to prevent the phosphorylation of the PDGF receptor type {beta}, extracellular signal-regulated kinase, or protein kinase B (PKB/Akt). Therefore, we conclude that the PDGF monomer is still active. The described antifibrotic effects are therefore mainly attributable to the structural impairment of TGF-{beta} signaling components reported previously.

  9. Diagnosis and characterization of GM 2 gangliosidosis type II (Sandhoff disease) by analysis of the accumulating N-acetyl-glucosaminyl oligosaccharides with high performance liquid chromatography.

    PubMed

    Warner, T G; De Kremer, R D; Applegarth, D; Mock, A K

    1986-02-15

    The N-acetyl-glucosaminyl oligosaccharides excreted in urine and accumulating in tissues of Sandhoff disease patients have been analyzed and characterized using a combination of high performance liquid chromatography and 500 MHz proton magnetic resonance spectroscopy. Delineation between infantile and juvenile onset forms of the disease was possible, as the latter forms had 6- to 13-fold lower levels of urinary oligosaccharides. Patients from a geographically isolated population deme in the La Rioja region of Argentina had urinary oligosaccharides similar to unrelated non-Argentinean patients with identical clinical phenotype. Together, these results indicate that the urinary oligosaccharides serve as useful indicators of the mutation differences or clinical heterogeneity within this disease only in cases of markedly differing clinical presentation. Analysis of the accumulating metabolites in liver, kidney, pancreas, lung and spleen, showed a similar oligosaccharide pattern which differed dramatically from brain. These results suggest the possibility of tissue specific regulation of oligosaccharide biosynthesis since there are notable differences between neural and visceral tissues.

  10. The multiple forms and kinetic properties of the N-acetyl-beta-D-hexosaminidases from colonic tumours and mucosa of rats treated with 1,2-dimethylhydrazine.

    PubMed Central

    Mian, N; Herries, D G; Cowen, D M; Batte, E A

    1979-01-01

    The separation and purification of the N-acetyl-beta-D-hexosaminidase activities from tumours induced by 1,2-dimethylhydrazine in the rat colon and from colonic mucosa of tumour-bearing animals are reported. Mucosa contained N-acetylhexosaminidases A and B, as well as a third form whose properties with regard to electrophoretic mobility and thermostability lay between those of A and B. Tumours contained only N-acetylhexosaminidase A and B activities. Each form possessed both N-acetylglucosaminidase (EC 3.2.1.30) and N-acetylgalactosaminidase (EC 3.2.1.53) activities, which could not be separated by a variety of techniques. The alteration of the ratio of the two specific activities in each form during purification, together with differences in the kinetic inhibition constants and behaviour during inactivation by various reagents or a temperature of 50 degrees C, supported the belief that each form contains the two enzyme activities, glucosaminidase and galactosaminidase, at separate active sites. This model is in contrast with that reported for these activities from a number of other sources. A variety of treatments reported to cause the conversion of form A into a form resembling B failed to produce such an effect on the rat colonic hexosaminidases. PMID:34391

  11. A histological and immunohistochemical study of the effects of N-acetyl cysteine on retinopathy of prematurity by modifying insulin-like growth factor-1.

    PubMed

    El-Hadidy, A R; El-Mohandes, E M; Asker, S A; Ghonaim, F M

    2016-08-01

    Retinopathy of prematurity (ROP) is a vasoproliferative disorder that occurs in premature infants and may lead to permanent visual impairment. We investigated both the possible protective role of N-acetyl cysteine (NAC) for preventing ROP and the role of IGF-1 in the disorder. Forty-five newborn rats were divided into three groups. Group 1 was raised in room air as controls. Group 2 was exposed to 60% oxygen for 14 days after birth, then transferred to room air. Group 3 was exposed to the same conditions as group 2, but received intraperitoneal injections of NAC on postnatal days 7-17. After 35 days, both eyes of all rats were processed for histology. Some sections were stained with hematoxylin and eosin to assess structural changes and other sections were immunostained to determine the location of IGF-1. Frozen sections also were prepared and stained for adenosine triphosphatase to detect retinal blood vessels. Compared to the controls, more blood vessels, many of which were abnormal, and increased IGF-1 expression were observed in group 2. In group 3, abnormal blood vessels and IGF-1 expression were less evident. NAC appeared to be an effective vascular-protective agent for ROP by decreasing IGF-1 expression.

  12. Effects of the monoamine oxidase inhibitor, tranylcypromine, on induction of HL60 cell differentiation by hexamethylene bisacetamide and N-acetyl-1,6-diaminohexane.

    PubMed

    Snyder, S W; Egorin, M J; Zuhowski, E G; Schimpff, E C; Callery, P S

    1990-01-01

    Hexamethylene bisacetamide (HMBA) is converted by successive deacetylation and oxidation reactions to four major metabolites; in vitro, the initial deacetylated metabolite, N-acetyl-1,6-diaminohexane (NAD-AH), is more potent than HMBA (Synder, S.W.; Egorin, M.J.; Geelhaar, L.A.; Hamburger, A.W.; Callery, P.S. Cancer Res. 48:3613-3616; 1988). We propose that monoamine oxidase (MAO) catalyzed metabolism of NADAH to 6-acetamidohexanoic acid (AcHA) is an inactivation pathway and, therefore, investigated whether blocking such metabolism with the MAO inhibitor, tranylcypromine, would potentiate induction of cell differentiation by HMBA and NADAH. Tranylcypromine, at concentrations up to 30 micrograms/mL, did not inhibit HL60 cell growth and did not induce differentiation of HL60 cells. Tranylcypromine did, however, produce concentration-dependent enhancement of HMBA- and NADAH-induced differentiation. In contrast, 30 micrograms/mL of tranylcypromine did not effect the ability of dimethylsulfoxide, at concentrations between 0.25% and 1.25%, to induce differentiation of HL60 cells. Tranylcypromine, at 30 micrograms/mL, did not change cellular concentrations of HMBA or NADAH but did reduce intracellular concentrations of AcHA, consistent with inhibition of MAO catalyzed conversion of NADAH to AcHA. These results support the hypothesis that MAO catalyzed metabolism of NADH to AcHA is an inactivation pathway and may provide the basis for a clinical trail in which HMBA metabolism is modulated with concurrent tranylcypromine therapy.

  13. N-Acetyl-seryl-aspartyl-lysyl-proline inhibits DNA synthesis in human mesangial cells via up-regulation of cell cycle modulators

    SciTech Connect

    Kanasaki, Keizo; Haneda, Masakazu; Sugimoto, Toshiro . E-mail: toshiro@belle.shiga-med.ac.jp; Shibuya, Kazuyuki; Isono, Motohide; Isshiki, Keiji; Araki, Shin-ichi; Uzu, Takashi; Kashiwagi, Atsunori; Koya, Daisuke

    2006-04-14

    N-Acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) was originally reported as a natural inhibitor of the proliferation of stem cells. To elucidate whether Ac-SDKP inhibits the proliferation of human mesangial cells, we examined the effect of Ac-SDKP on fetal calf serum (FCS)- or platelet-derived growth factor (PDGF)-BB-induced DNA synthesis and a cell proliferation. Ac-SDKP inhibited PDGF-BB- or FCS-induced DNA synthesis without cellular toxicity. The protein expression of p53 and p27{sup kip1} was significantly increased by Ac-SDKP. Ac-SDKP also up-regulated the PDGF-BB-stimulated expression of p21{sup cip1} and suppressed PDGF-BB-induced cyclin D{sub 1} expression. In p53 knock-out human mesangial cells made with small interference RNA, the protein expression of p21{sup cip1} and p27{sup kip1} was also decreased and the inhibitory effect of Ac-SDKP on mesangial proliferation was completely abolished. Ac-SDKP increased the stability of p53 protein as demonstrated by pulse-chase experiment. These results suggest that p53 is the key mediator of Ac-SDKP-induced inhibition of DNA synthesis through the up-regulation of cell cycle modulators, highlighting a potential effect of Ac-SDKP on various progressive renal diseases.

  14. Phosphorescence detection of L-ascorbic acid with surface-attached N-acetyl-L-cysteine and L-cysteine Mn doped ZnS quantum dots.

    PubMed

    Bian, Wei; Ma, Jing; Guo, Wenrong; Lu, Dongtao; Fan, Meng; Wei, Yanli; Li, Yingfu; Shuang, Shaomin; Choi, Martin M F

    2013-11-15

    N-Acetyl-L-cysteine (NAC) and L-cysteine (Cys) capped Mn doped ZnS quantum dots (NAC-Mn/ZnS QDs and Cys-Mn/ZnS QDs) are firstly prepared by hydrothermal methods. These QDs display strong phosphorescence emission peaks at 583 and 580 nm upon excitation at 315 and 306 nm, respectively. Since their room-temperature phosphorescence is efficiently quenched by L-ascorbic acid (AA), they have been employed as phosphorescence probes for detecting AA. The linear working ranges are 2.5-37.5 and 2.5-47.5 µM and the limits of detection are 0.72 and 1.38 µM for NAC-Mn/ZnS QDs and Cys-Mn/ZnS QDs, respectively. The possible quenching mechanisms have been discussed in detail. The QDs probes are highly selective to AA over other common ions, amino acids, glucose and bovine serum album. Finally, they have been applied successfully for detection of AA in human urine samples with satisfactory results. The recoveries are 98-104%. Our work provides a simple and convenient phosphorescence method to determine AA in real samples.

  15. Oxidative stress mediated cytotoxicity of cyanide in LLC-MK2 cells and its attenuation by alpha-ketoglutarate and N-acetyl cysteine.

    PubMed

    Hariharakrishnan, J; Satpute, R M; Prasad, G B K S; Bhattacharya, R

    2009-03-10

    Cyanide is a rapidly acting mitochondrial poison that inhibits cellular respiration and energy metabolism leading to histotoxic hypoxia followed by cell death. Cyanide is predominantly a neurotoxin but its toxic manifestations in non-neuronal cells are also documented. This study addresses the oxidative stress mediated cytotoxicity of cyanide in Rhesus monkey kidney epithelial cells (LLC-MK2). Cells were treated with various concentrations of potassium cyanide (KCN) for different time intervals and cytotoxicity was evidenced by increased leakage of intracellular lactate dehydrogenase, mitochondrial dysfunction (MTT assay) and depleted energy status of cells (ATP assay). Cytotoxicity was accompanied by lipid peroxidation indicated by elevated levels of malondialdehyde (MDA), reactive oxygen species (ROS) and reactive nitrogen species (RNS) (DCF-DA staining), diminished cellular antioxidant status (reduced glutathione (GSH), glutathione peroxidase, superoxide dismutase and catalase). These cascading events triggered an apoptotic kind of cell death characterized by oligonucleosomal DNA fragmentation and nuclear fragmentation (Hoechst 33342 staining). Apoptosis was further confirmed by increased caspase-3 activity. Cyanide-induced cytotoxicity, oxidative stress, and DNA fragmentation were prevented by alpha-ketoglutarate (A-KG) and N-acetyl cysteine (NAC). A-KG is a potential cyanide antidote that confers protection by interacting with cyanide to form cyanohydrin complex while NAC is a free radical scavenger and enhances the cellular GSH levels. The study reveals cytotoxicity of cyanide in cells of renal origin and the protective efficacy of A-KG and NAC.

  16. Investigation of the association behaviors between bovine serum albumin and 2-(4-methylphenyl)-3-(N-acetyl)-5-(2,4-dichlorophenoxymethyl)-1,3,4-oxodiazoline

    NASA Astrophysics Data System (ADS)

    Huang, Zhenzhong; Wang, Ruiling; Han, Erwei; Xu, Lifan; Song, Yonghai

    2013-07-01

    The study was designed to examine the interaction between 2-(4-methylphenyl)-3-(N-acetyl)-5-(2,4-dichlorophenoxymethyl)-1,3,4-oxodiazoline (MPNDO) and bovine serum albumin (BSA) under physiological conditions by using fluorescence spectroscopy, ultraviolet absorption spectroscopy, FT-IR spectroscopy and circular dichroism spectroscopy and atomic force microscope. Spectroscopic analysis of the fluorescence emission quenching and ultraviolet absorption revealed that the quenching mechanism of bovine serum albumin by MPNDO was static quenching procedure. The binding constant and binding sites number at different temperatures were measured. The average binding distances between donor (BSA) and acceptor (MPNDO) was estimated to be 1.46 nm (301 K), based on the Föster non-radioactive energy transfer theory. An average size of 3.1 nm had a high proportion and these dots might be ascribed to BSA, some other dots with an average size of 6.6 nm might result from BSA-MPNDO bioconjugates while the average diameter of MPNDO was 1.6 nm, which was reasonable to conclude that one BSA-MPNDO bioconjugates consisted of one BSA and one MPNDO. The thermodynamic parameters, enthalpy change (ΔH), entropy change (ΔS) and free energy change (ΔG) were calculated, which indicated that the action force was mainly van der Waals forces. The data collected through synchronous fluorescence, FT-IR spectroscopy and circular dichroism spectroscopy demonstrated that the conformation of BSA was not affected obviously in the presence of MPNDO.

  17. A reliable method of liquid chromatography for the quantification of acetaminophen and identification of its toxic metabolite N-acetyl-p-benzoquinoneimine for application in pediatric studies.

    PubMed

    Flores-Pérez, Carmen; Chávez-Pacheco, Juan Luis; Ramírez-Mendiola, Blanca; Alemón-Medina, Radamés; García-Álvarez, Raquel; Juárez-Olguín, Hugo; Flores-Pérez, Janett

    2011-07-01

    The aim of the present study was to develop a simple, selective and reliable method to quantify acetaminophen and its toxic metabolite N-acetyl-p-benzoquinoneimine (NAPQI) for pediatric studies using 100 µL plasma samples, by reverse-phase HPLC and UV detection. The assay was performed using a C₁₈ column and an isocratic elution with water-methanol-formic acid (70:30:0.15; v/v/v) as mobile phase. Linearity of the method was assayed in the range of 1-30 µg/mL for acetaminophen and 10-200 µg/mL for NAPQI, with a correlation coefficient r = 0.999 for both compounds, and inter- and intra-day coefficients of variation of less than 13%. Several commonly co-administered drugs were analyzed for selectivity and no interference with the determinations was observed. The detection and quantification limits for acetaminophen and NAPQI were 0.1 and 1 µg/mL, and 0.1 and 10 µg/mL respectively. The present method can be used to monitor acetaminophen levels using 100 µL plasma samples, which may be helpful when very small samples need to be analyzed, as in pharmacokinetics determination or drug monitoring in plasma in children. This assay is also able to detect the NAPQI for drug monitoring in patients diagnosed with acetaminophen intoxication. Copyright © 2010 John Wiley & Sons, Ltd.

  18. Isolation and characterization of two N-acetyl-D-lactosamine specific lectins from tubers of Arisaema intermedium Blume and A. wallichianum Hook f.

    PubMed

    Kaur, Manpreet; Singh, Jatinder; Kamboj, Sukhdev Singh; Singh, Jagmohan; Kaur, Amandeep; Sood, S K; Saxena, A K

    2005-02-01

    Two new lectins were purified from the tubers of Arisaema intermedium Blume and A. wallichianum Hook. f. (family: Araceae) by affinity chromatography on asialofetuin-linked amino activated silica beads. The bound lectins were eluted with 0.1 M glycine-HCl, pH 2.5. They gave a single band corresponding to subunit M(r) 13.4 kDa in SDS-PAGE, pH 8.3. On gel filtration chromatography, the lectins showed a M(r) of 51.2 kDa, suggesting a homotetrameric structure. Both the lectins gave a single peak on size exclusion HPLC and cation-exchange columns and a single band on PAGE, pH 4.5. However, like other monocot lectins, they gave multiple bands in isoelectric focusing and at PAGE 8.3. The lectins were inhibited by N-acetyl-D-lactosamine (LacNAc), a disaccharide and asialofetuin, a complex desialylated serum glycoprotein. They had no requirement for divalent metal ions i.e., Ca2+ and Mn2+ for their activity and were found to be mitogenic towards human lymphocytes. A. intermedium showed antiproliferative effect against various human cancer cell lines in vitro.

  19. Potential of N-acetylated-para-aminosalicylic Acid to Accelerate Manganese Enhancement Decline for Long-term MEMRI in Rodent Brain

    PubMed Central

    Bade, Aditya N; Zhou, Biyun; McMillan, JoEllyn; Narayanasamy, Prabagaran; Veerubhotla, Ram; Gendelman, Howard E; Boska, Michael D; Liu, Yutong

    2015-01-01

    Background Manganese (Mn2+)-enhanced MRI (MEMRI) is a valuable imaging tool to study brain structure and function in normal and diseased small animals. The brain retention of Mn2+ is relatively long with a half-life (t1/2) of 51 to 74 days causing a slow decline of MRI signal enhancement following Mn2+ administration. Such slow decline limits using repeated MEMRI to follow the central nervous system longitudinally in weeks or months. This is because residual Mn2+ from preceding administrations can confound the interpretation of imaging results. We investigated whether the Mn2+ enhancement decline could be accelerated thus enabling repeated MEMRI, and as a consequence broadens the utility of MEMRI tests. New Methods We investigated whether N-acetyl-para-aminosalicylic acid (AcPAS), a chelator of Mn2+, could affect the decline of Mn2+ induced MRI enhancement in brain. Results and Conclusion Two-week treatment with AcPAS (200 mg/kg/dose × 3 daily) accelerated the decline of Mn2+ induced enhancement in MRI. In the whole brain on average the enhancement declined from 100% to 17% in AcPAS treated mice, while in PBS controls the decline is from 100% to 27%. We posit that AcPAS could enhance MEMRI utility for evaluating brain biology in small animals. Comparison with Existing Methods To the best of our knowledge, no method exists to accelerate the decline of the Mn2+ induced MRI enhancement for repeated MEMRI tests. PMID:26004847

  20. Oral Administration of N-Acetyl-seryl-aspartyl-lysyl-proline Ameliorates Kidney Disease in Both Type 1 and Type 2 Diabetic Mice via a Therapeutic Regimen

    PubMed Central

    Nitta, Kyoko; Shi, Sen; Nagai, Takako; Kanasaki, Megumi; Kitada, Munehiro; Srivastava, Swayam Prakash; Haneda, Masakazu; Kanasaki, Keizo; Koya, Daisuke

    2016-01-01

    Kidney fibrosis is the final common pathway of progressive kidney diseases including diabetic nephropathy. Here, we report that the endogenous antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP), the substrate of angiotensin-converting enzyme (ACE), is an orally available peptide drug used to cure kidney fibrosis in diabetic mice. We utilized two mouse models of diabetic nephropathy, streptozotocin- (STZ-) induced type 1 diabetic CD-1 mice and type 2 diabetic nephropathy model db/db mice. Intervention with the ACE inhibitor imidapril, oral AcSDKP, or imidapril + oral AcSDKP combination therapy increased urine AcSDKP levels. AcSDKP levels were significantly higher in the combination group compared to those of the other groups. AcSDKP oral administration, either AcSDKP alone or in addition to imidapril, ameliorated glomerulosclerosis and tubulointerstitial fibrosis. Plasma cystatin C levels were higher in both models, at euthanasia, and were restored by all the treatment groups. The levels of antifibrotic miRs, such as miR-29 or let-7, were suppressed in the kidneys of both models; all treatments, especially the combination of imidapril + oral AcSDKP, restored the antifibrotic miR levels to a normal value or even higher. AcSDKP may be an oral antifibrotic peptide drug that would be relevant to combating fibroproliferative kidney diseases such as diabetic nephropathy. PMID:27088094

  1. Role of excited-state hydrogen detachment and hydrogen-transfer processes for the excited-state deactivation of an aromatic dipeptide: N-acetyl tryptophan methyl amide.

    PubMed

    Shemesh, Dorit; Sobolewski, Andrzej L; Domcke, Wolfgang

    2010-05-21

    The excited-state electronic potential-energy surfaces of the three conformers of the capped dipeptide N-acetyl tryptophan methyl amide (NATMA), for which UV and IR spectra have been reported by Dian et al. [J. Chem. Phys., 2003, 118, 2696], have been explored with ab initio electronic-structure methods. The results provide insight into the nonadiabatic electronic coupling mechanisms which are responsible for the pronounced and conformer-specific perturbations of the spectra, such as broad and congested UV spectra as well as the deletion of certain fundamentals in the IR spectrum of the S(1) state. It is shown that the photophysical dynamics of NATMA is governed by at least five excited singlet electronic states: the two spectroscopic (1)L(b) and (1)L(a) states and the dissociative (1)pisigma* state of the indole chromophore, as well as a locally-excited state and a charge-transfer state of the peptide backbone. For the conformer NATMA C, which exhibits a gamma-turn of the backbone, a potentially very efficient excited-state deactivation mechanism to the electronic ground state via three conical intersections has been revealed. The results confirm the important role of hydrogen bonds for rapid excited-state deactivation of peptides, which enhances their photostability.

  2. Effects of N-acetyl-L-cysteine-capped CdTe quantum dots on bovine serum albumin and bovine hemoglobin: isothermal titration calorimetry and spectroscopic investigations.

    PubMed

    Sun, Haoyu; Cui, Erqian; Tan, Zhigang; Liu, Rutao

    2014-12-01

    The interactions of N-acetyl-L-cysteine-capped CdTe quantum dots (QDs) with bovine serum albumin (BSA) and bovine hemoglobin (BHb) were investigated by isothermal titration calorimetry (ITC), fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible absorption, and circular dichroism techniques. Fluorescence data of BSA-QDs and BHb-QDs revealed that the quenching was static in every system. While CdTe QDs changed the microenvironment of tryptophan in BHb, the microenvironment of BSA kept unchanged. Adding CdTe QDs affected the skeleton and secondary structure of the protein (BSA and BHb). The ITC results indicated that the interaction between the protein (BSA and BHb) and QDs-612 was spontaneous and the predominant force was hydrophobic interaction. In addition, the binding constants were determined to be 1.19 × 10(5) L mol(-1) (BSA-QDs) and 2.19 × 10(5) L mol(-1) (BHb-QDs) at 298 K. From these results, we conclude that CdTe QDs have a larger impact on the structure of BHb than BSA.

  3. Simultaneous determination of individual isothiocyanates in plant samples by HPLC-DAD-MS following SPE and derivatization with N-acetyl-l-cysteine.

    PubMed

    Pilipczuk, Tadeusz; Kusznierewicz, Barbara; Chmiel, Tomasz; Przychodzeń, Witold; Bartoszek, Agnieszka

    2017-01-01

    The procedure for the isothiocyanates (ITCs) determination that involves derivatization with N-acetyl-l-cysteine (NAC) and separation by HPLC was developed. Prior to derivatization, plant ITCs were isolated and purified using solid-phase extraction (SPE). The optimum conditions of derivatization are: 500μL of isopropanolic eluate obtained by SPE combined with 500μL of derivatizing reagent (0.2M NAC and 0.2M NaHCO3 in water) and reaction time of 1h at 50°C. The formed dithiocarbamates are directly analyzed by HPLC coupled with diode array detector and mass spectrometer if required. The method was validated for nine common natural ITCs. Calibration curves were linear (R(2)⩾0.991) within a wide range of concentrations and limits of detection were below 4.9nmol/mL. The recoveries were in the range of 83.3-103.7%, with relative standard deviations <5.4%. The developed method has been successfully applied to determine ITCs in broccoli, white cabbage, garden cress, radish, horseradish and papaya. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Transport of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine, a metabolite of trichloroethylene, by mouse multidrug resistance associated protein 2 (Mrp2)

    SciTech Connect

    Tsirulnikov, Kirill; Abuladze, Natalia; Koag, Myong-Chul; Newman, Debra; Bondar, Galyna; Zhu Quansheng; Dekant, Wolfgang; Faull, Kym; Kurtz, Ira

    2010-04-15

    N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (Ac-DCVC) and S-(1,2-dichlorovinyl)-L-cysteine (DCVC) are the glutathione conjugation pathway metabolites of a common industrial contaminant and potent nephrotoxicant trichloroethylene (TCE). Ac-DCVC and DCVC are accumulated in the renal proximal tubule where they may be secreted into the urine by an unknown apical transporter(s). In this study, we explored the hypothesis that the apical transport of Ac-DCVC and/or DCVC may be mediated by the multidrug resistance associated protein 2 (Mrp2, ABCC2), which is known to mediate proximal tubular apical ATP-dependent transport of glutathione and numerous xenobiotics and endogenous substances conjugated with glutathione. Transport experiments using membrane vesicles prepared from mouse proximal tubule derived cells expressing mouse Mrp2 utilizing ATPase assay and direct measurements of Ac-DCVC/DCVC using liquid chromatography/tandem mass-spectrometry (LC/MS/MS) demonstrated that mouse Mrp2 mediates ATP-dependent transport of Ac-DCVC. Expression of mouse Mrp2 antisense mRNA significantly inhibited the vectorial basolateral to apical transport of Ac-DCVC but not DCVC in mouse proximal tubule derived cells endogenously expressing mouse Mrp2. The results suggest that Mrp2 may be involved in the renal secretion of Ac-DCVC.

  5. N-acetyl cysteine restores brain glutathione loss in combined 2-cyclohexene-1-one and d-amphetamine-treated rats: relevance to schizophrenia and bipolar disorder.

    PubMed

    Dean, Olivia M; van den Buuse, Maarten; Berk, Michael; Copolov, David L; Mavros, Christine; Bush, Ashley I

    2011-07-25

    Oxidative stress and reduced brain levels of glutathione have been implicated in schizophrenia and bipolar disorder. N-acetyl cysteine (NAC) is a precursor of glutathione and has additional effects on glutamate neurotransmission, neurogenesis and inflammation. While NAC treatment has shown benefits in both schizophrenia and bipolar disorder, the mechanisms of action are largely unknown. Similarly, the interaction between oxidative stress and altered dopaminergic activities in psychiatric illness is not yet characterized. This study investigated the capacity of NAC in restoring brain glutathione depletion in rats that received 2-cyclohexene-1-one (CHX, 75 mg/kg), d-amphetamine (2.5mg/kg) or both. CHX, but not amphetamine, induced significant depletion of glutathione levels in the striatum and frontal cortex. Glutathione depletion was reversed by NAC (1000 mg/kg) in saline-treated and amphetamine-treated (frontal cortex only) rats. While NAC was shown to be beneficial in this model, the lack of additional glutathione depletion by amphetamine in combination with CHX does not support a summative interaction between oxidative stress and altered dopamine transmission.

  6. S-Nitroso-N-acetyl-D-penicillamine covalently linked to polydimethylsiloxane (SNAP-PDMS) for use as a controlled photoinitiated nitric oxide release polymer

    NASA Astrophysics Data System (ADS)

    Gierke, Genevieve E.; Nielsen, Matthew; Frost, Megan C.

    2011-10-01

    Nitric oxide (NO) plays a critical role in the regulation of a wide variety of physiological processes. It is a potent inhibitor of platelet adhesion and aggregation, inhibits bacterial adhesion and proliferation, is implicated in mediating the inflammatory response toward implanted devices, plays a role in tumor growth and proliferation, and is a neurotransmitter. Herein, we describe the synthesis and NO-release properties of a modified polydimethylsiloxane that contains S-nitroso-N-acetyl-D-penicillamine covalently attached to the cross-linking agent (SNAP-DMS). Light from a C503B-BAN-CY0C0461 light-emitting diode (470 nm) was used as an external trigger to allow precise control over level and duration of NO release ranging from a surface flux of zero to approximately 3.5×10-10 mol cm-2 min-1. SNAP-PDMS films stored in the dark released NO after 297 days, indicating the long-term stability of SNAP-PDMS.

  7. Binding Structures of tri-N-acetyl-β-glucosamine in Hen Egg White Lysozyme using Molecular Dynamics with a Polarizable Force Field

    PubMed Central

    Zhong, Yang; Patel, Sandeep

    2014-01-01

    Lysozyme is a well-studied enzyme that hydrolyzes the β-(1,4)-glycosidic linkage of N-acetyl-β-glucosamine (NAG)n oligomers. The active site of hen egg-white lysozyme (HEWL) is believed to consist of six subsites, A-F that can accommodate six sugar residues. We present studies exploring the use of polarizable force fields in conjunction with all-atom molecular dynamics simulations to analyze binding structures of complexes of lysozyme and NAG trisaccharide, (NAG)3. Molecular dynamics trajectories are applied to analyze structures and conformation of the complex as well as protein-ligand interactions, including the hydrogen-bonding network in the binding pocket. Two binding modes (ABC and BCD) of (NAG)3 are investigated independently based on a fixed-charge model and a polarizable model. We also apply MM-GBSA methods based on molecular dynamics using both non-polarizable and polarizable force fields in order to compute binding free energies. We also study the correlation between RMSD and binding free energies of the wildtype and W62Y mutant; we find that for this prototypical system, approaches using the MD trajectories coupled with implicit solvent models are equivalent for polarizable and fixed-charge models. PMID:23109228

  8. Chiral recognition of phenylglycinol enantiomers based on N-acetyl-L-cysteine capped CdTe quantum dots in the presence of Ag+

    NASA Astrophysics Data System (ADS)

    Guo, Yuan; Zeng, Xiaoqing; Yuan, Haiyan; Huang, Yunmei; Zhao, Yanmei; Wu, Huan; Yang, Jidong

    2017-08-01

    In this study, a novel method for chiral recognition of phenylglycinol (PG) enantiomers was proposed. Firstly, water-soluble N-acetyl-L-cysteine (NALC)-capped CdTe quantum dots (QDs) were synthesized and experiment showed that the fluorescence intensity of the reaction system slightly enhancement when added PG enantiomers to NALC-capped CdTe quantum dots (QDs), but the R-PG and S-PG could not be distinguished. Secondly, when there was Ag+ presence in the reaction system, the experiment result was extremely interesting, the PG enantiomers cloud make NALC-capped CdTe QDs produce different fluorescence signal, in which the fluorescence of S-PG + Ag+ + NALC-CdTe system was significantly enhanced, and the fluorescence of R-PG + Ag+ + NALC-CdTe system was markedly decreased. Thirdly, all the enhanced and decreased of the fluorescence intensity were directly proportional to the concentration of R-PG and S-PG in the linearly range 10- 5-10- 7 mol·L- 1, respectively. So, the new method for simultaneous determination of the PG enantiomers was built too. The experiment result of the method was satisfactory with the detection limit of PG can reached 10- 7 mol·L- 1 and the related coefficient of S-PG and R-PG are 0.995 and 0.980, respectively. The method was highly sensitive, selective and had wider detection range compared with other methods.

  9. Molecular cloning and characterization of a cDNA encoding the N-acetyl-beta-D-glucosaminidase homologue of Paracoccidioides brasiliensis.

    PubMed

    Santos, Mônica O; Pereira, Maristela; Felipe, Maria Sueli S; Jesuino, Rosalia Santos A; Ulhoa, Cirano J; Soares, Renata de Bastos A; Soares, Celia Maria de A

    2004-06-01

    A cDNA encoding the N-acetyl-beta-D-glucosaminidase (NAG) protein of Paracoccidioides brasiliensis, Pb NAG1, was cloned and characterized. The 2663-nucleotide sequence of the cDNA consisted of a single open reading frame encoding a protein with a predicted molecular mass of 64.73 kDa and an isoeletric point of 6.35. The predicted protein includes a putative 30-amino-acid signal peptide. The protein as a whole shares considerable sequence similarity with 'classic' NAG. The primary sequence of Pb NAG1 was used to infer phylogenetic relationships. The amino acid sequence of Pb NAG1 has 45, 31 and 30% identity, respectively, with homologous sequences from Trichoderma harzianum, Aspergillus nidulans and Candida albicans. In particular, striking homology was observed with the active site regions of the glycosyl hydrolase group of proteins (family 20). The expected active site consensus motif G X D E and catalytic Asp and Glu residues at positions 373 and 374 were found, reinforcing that Pb NAG1 belongs to glycosyl hydrolase family 20. The nucleotide sequence of Pb nag1 and its flanking regions have been deposited, along with the amino acid sequence of the deduced protein, in GenBank under accession number AF419158.

  10. N-acetyl-cysteine prevents age-related hearing loss and the progressive loss of inner hair cells in γ-glutamyl transferase 1 deficient mice

    PubMed Central

    Ding, Dalian; Jiang, Haiyan; Chen, Guang-Di; Longo-Guess, Chantal; Muthaiah, Vijaya Prakash Krishnan; Tian, Cong; Sheppard, Adam; Salvi, Richard; Johnson, Kenneth R.

    2016-01-01

    Genetic factors combined with oxidative stress are major determinants of age-related hearing loss (ARHL), one of the most prevalent disorders of the elderly. Dwarf grey mice, Ggt1dwg/dwg, are homozygous for a loss of function mutation of the γ-glutamyl transferase 1 gene, which encodes an important antioxidant enzyme critical for the resynthesis of glutathione (GSH). Since GSH reduces oxidative damage, we hypothesized that Ggt1dwg/dwg mice would be susceptible to ARHL. Surprisingly, otoacoustic emissions and cochlear microphonic potentials, which reflect cochlear outer hair cell (OHC) function, were largely unaffected in mutant mice, whereas auditory brainstem responses and the compound action potential were grossly abnormal. These functional deficits were associated with an unusual and selective loss of inner hair cells (IHC), but retention of OHC and auditory nerve fibers. Remarkably, hearing deficits and IHC loss were completely prevented by N-acetyl-L-cysteine, which induces de novo synthesis of GSH; however, hearing deficits and IHC loss reappeared when treatment was discontinued. Ggt1dwg/dwgmice represent an important new model for investigating ARHL, therapeutic interventions, and understanding the perceptual and electrophysiological consequences of sensory deprivation caused by the loss of sensory input exclusively from IHC. PMID:26977590

  11. Oral Administration of N-Acetyl-seryl-aspartyl-lysyl-proline Ameliorates Kidney Disease in Both Type 1 and Type 2 Diabetic Mice via a Therapeutic Regimen.

    PubMed

    Nitta, Kyoko; Shi, Sen; Nagai, Takako; Kanasaki, Megumi; Kitada, Munehiro; Srivastava, Swayam Prakash; Haneda, Masakazu; Kanasaki, Keizo; Koya, Daisuke

    2016-01-01

    Kidney fibrosis is the final common pathway of progressive kidney diseases including diabetic nephropathy. Here, we report that the endogenous antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP), the substrate of angiotensin-converting enzyme (ACE), is an orally available peptide drug used to cure kidney fibrosis in diabetic mice. We utilized two mouse models of diabetic nephropathy, streptozotocin- (STZ-) induced type 1 diabetic CD-1 mice and type 2 diabetic nephropathy model db/db mice. Intervention with the ACE inhibitor imidapril, oral AcSDKP, or imidapril + oral AcSDKP combination therapy increased urine AcSDKP levels. AcSDKP levels were significantly higher in the combination group compared to those of the other groups. AcSDKP oral administration, either AcSDKP alone or in addition to imidapril, ameliorated glomerulosclerosis and tubulointerstitial fibrosis. Plasma cystatin C levels were higher in both models, at euthanasia, and were restored by all the treatment groups. The levels of antifibrotic miRs, such as miR-29 or let-7, were suppressed in the kidneys of both models; all treatments, especially the combination of imidapril + oral AcSDKP, restored the antifibrotic miR levels to a normal value or even higher. AcSDKP may be an oral antifibrotic peptide drug that would be relevant to combating fibroproliferative kidney diseases such as diabetic nephropathy.

  12. Serum and urine N-acetyl-beta-D-glucosaminidase in diabetics on diagnosis and subsequent treatment, and stable insulin dependent diabetics.

    PubMed

    Whiting, P H; Ross, I S; Borthwick, L

    1979-03-15

    N-Acetyl-beta-D-glucosaminidase (NAG) activity has been measured in the serum and urine of diabetics. Results have shown significantly higher levels of serum NAG in newly diagnosed diabetics (945 +/- 372 units/ml) compared to non-diabetic controll (668 +/- 225, p less than 0.005) and the levels were reduced by treatment (778 +/- 218, p less than 0.05). Changes occurred in the same direction when urinary NAG was measured falling from a mean of 572 +/- 298 units/mg urinary creatinine, on diagnosis to 291 +/- 176 after treatment (p less than 0.005), as compared with 177 +/- 86 in non-diabetic controls. Established insulin-treated diabetics had a urinary NAG activity of 461 +/- 440 and a serum NAG activity of 790 +/- 245. No correlation was found between urine NAG activity and urine glucose (r = 0.315), or serum NAG and serum glucose (r = 0.273). An assessment of this enzyme is made in relation to early microangiopathy.

  13. Fabrication of nonwoven fabrics consisting of gelatin nanofibers cross-linked by glutaraldehyde or N-acetyl-d-glucosamine by aqueous method.

    PubMed

    Furuike, Tetsuya; Chaochai, Thitirat; Okubo, Tsubasa; Mori, Takahiro; Tamura, Hiroshi

    2016-12-01

    Since gelatin (Gel) undergoes a sol-gel transition, a novel dry-spinning procedure for Gel was used. Here, nonwoven fabrics of Gel were electrospun by applying the principles of dry spinning. The diameter of the fibers and the viscosity and flow rate of the solution were directly dependent on the concentration of Gel. Nonwoven fabrics spun with a 25% (w/w) Gel concentration only exhibited a nanoscale fiber diameter. In order to improve the properties of the nonwoven fabrics, they were cross-linked with glutaraldehyde (GTA) vapor after spinning or by the addition of N-acetyl-d-glucosamine (GlcNAc) to the Gel solution prior to spinning followed by heating these fibers. The developed nonwoven fibers were characterized using SEM, rheometry, FTIR, TGA, and mechanical tensile testing. The nonwoven fabrics cross-linked by the GTA vapor exhibited improved mechanical properties compared to those without cross-linking or with GlcNAc cross-linking. The swelling and water uptake ability resulted in no morphological changes in the fibers with GTA cross-linking. The TGA thermogram confirmed no phase change in the composite structure. Further, in vitro cytocompatibility studies using human mesenchymal stem cells showed the compatible nature of the developed nonwoven fibers. Our studies showed that these nonwoven fibers could be useful in medical care.

  14. Enzymic synthesis of 3'-O- and 6'-O-N-acetylglucosaminyl-N-acetyllactosaminide glycosides catalyzed by beta-N-acetyl-D-hexosaminidase from Nocardia orientalis.

    PubMed

    Murata, T; Tashiro, A; Itoh, T; Usui, T

    1997-06-06

    beta-N-acetyl-D-hexosaminidase from Nocardia orientalis catalyzed the synthesis of beta-D-GlcNAc-(1 --> 3)-beta-D-Gal-(1 --> 4)-beta-D-GlcNAc-OC6H4NO2-p (1) and beta-D-GlcNAc-(1 --> 6)-beta-D-Gal-(1 --> 4)-beta-D-GlcNAc-OC6H4NO2-p (2) with its isomer beta-D-Gal-(1 --> 4)-[beta-D-GlcNAc-(1 --> 6)]-beta-D-GlcNAc-OC6H4NO2-p (3) through N-acetylglucosaminyl transfer from N-,N'-diacetylchitobiose to p-nitrophenyl beta-N-acetyllactosaminide. The enzyme formed a mixture of trisaccharides 1, 2, and 3 in a ratio of 11:33:56. In the case, when an inclusion complex of p-nitrophenyl beta-N-acetyllactosaminide with alpha-CD was used, compounds 1, 2, and 3 were formed in a molar ratio of 24:63:13. The regioselectivity of glycosidase-catalyzed formation of the trisaccharide glycosides was substantially changed. It resulted not only in a significant increase of the proportion of the desired compounds 1 and 2 but also in the substantial increase of the overall yield of transfer products.

  15. MicroRNA-214 Suppresses Growth and Invasiveness of Cervical Cancer Cells by Targeting UDP-N-acetyl-α-d-galactosamine:Polypeptide N-Acetylgalactosaminyltransferase 7*

    PubMed Central

    Peng, Rui-Qing; Wan, Hai-Ying; Li, Hai-Fang; Liu, Min; Li, Xin; Tang, Hua

    2012-01-01

    MicroRNAs are a class of small noncoding RNAs that function as key regulators of gene expression at the post-transcriptional level. In this study, we demonstrate that miR-214 is frequently down-regulated in cervical cancer, and its expression reduces the proliferation, migration, and invasiveness of cervical cancer cells, whereas inhibiting its expression results in enhanced proliferation, migration, and invasion. miR-214 binds to the 3′-UTR of UDP-N-acetyl-α-d-galactosamine:polypeptide N-acetylgalactosaminyltransferase 7 (GALNT7), thereby repressing GALNT7 expression. Furthermore, we are the first to show, using quantitative real-time PCR, that GALNT7 is frequently up-regulated in cervical cancer. The knockdown of GALNT7 markedly inhibits cervical cancer cell proliferation, migration, and invasion, whereas ectopic expression of GALNT7 significantly enhances these properties, indicating that GALNT7 might function as an oncogene in cervical cancer. The restoration of GALNT7 expression can counteract the effect of miR-214 on cell proliferation, migration, and invasiveness of cervical cancer cells. Together, these results indicate that miR-214 is a new regulator of GALNT7, and both miR-214 and GALNT7 play important roles in the pathogenesis of cervical cancer. PMID:22399294

  16. Antioxidant N-acetyl-L-cysteine ameliorates symptoms of premature aging associated with the deficiency of the circadian protein BMAL1.

    PubMed

    Kondratov, Roman V; Vykhovanets, Olena; Kondratova, Anna A; Antoch, Marina P

    2009-12-30

    Deficiency of the circadian clock protein BMAL1 leads to premature aging and increased levels of reactivate oxygen species in several tissues of mice. In order to investigate the role of oxidative stress in accelerated aging and development of age-related pathologies, we continuously administered the antioxidant N-acetyl-L-cysteine toBmal1-deficient mice through their entire lifespan by supplementing drinking water. We found that the life long treatment with antioxidant significantly increased average and maximal lifespan and reduced the rate of age-dependent weight loss and development of cataracts. At the same time, it had no effect on time of onset and severity of other age-related pathologies characteristic of Bmal1-/- mice, such as joint ossification, reduced hair regrowth and sarcopenia. We conclude that chronic oxidative stress affects longevity and contributes to the development of at least some age-associated pathology, although ROS-independent mechanisms may also play a role. Our bioinformatics analysis identified the presence of a conservative E box element in the promoter regions of several genes encoding major antioxidant enzymes. We speculate that BMAL1 controls antioxidant defense by regulating the expression of major antioxidant enzymes.

  17. The acetaminophen metabolite N-acetyl-p-benzoquinone imine (NAPQI) inhibits glutathione synthetase in vitro; a clue to the mechanism of 5-oxoprolinuric acidosis?

    PubMed

    Walker, Valerie; Mills, Graham A; Anderson, Mary E; Ingle, Brandall L; Jackson, John M; Moss, Charlotte L; Sharrod-Cole, Hayley; Skipp, Paul J

    2017-02-01

    1. Metabolic acidosis due to accumulation of l-5-oxoproline is a rare, poorly understood, disorder associated with acetaminophen treatment in malnourished patients with chronic morbidity. l-5-Oxoprolinuria signals abnormal functioning of the γ-glutamyl cycle, which recycles and synthesises glutathione. Inhibition of glutathione synthetase (GS) by N-acetyl-p-benzoquinone imine (NAPQI) could contribute to 5-oxoprolinuric acidosis in such patients. We investigated the interaction of NAPQI with GS in vitro. 2. Peptide mapping of co-incubated NAPQI and GS using mass spectrometry demonstrated binding of NAPQI with cysteine-422 of GS, which is known to be essential for GS activity. Computational docking shows that NAPQI is properly positioned for covalent bonding with cysteine-422 via Michael addition and hence supports adduct formation. 3. Co-incubation of 0.77 μM of GS with NAPQI (25-400 μM) decreased enzyme activity by 16-89%. Inhibition correlated strongly with the concentration of NAPQI and was irreversible. 4. NAPQI binds covalently to GS causing irreversible enzyme inhibition in vitro. This is an important novel biochemical observation. It is the first indication that NAPQI may inhibit glutathione synthesis, which is pivotal in NAPQI detoxification. Further studies are required to investigate its biological significance and its role in 5-oxoprolinuric acidosis.

  18. An improved sample preparation for an LC method used in the age estimation based on aspartic acid racemization from human dentin.

    PubMed

    Yekkala, Raja; Meers, Carine; Hoogmartens, Jos; Lambrichts, Ivo; Willems, Guy; Van Schepdael, Ann

    2007-01-01

    The determination of age on the basis of aspartic acid (Asp) racemization in teeth is one of the most reliable and accurate methods to date. In this paper, the usefulness of HPLC coupled with fluorescence detection for determination of Asp racemization was evaluated. A modified sample preparation is proposed for better stability of o-phthaldialdehyde-N-acetyl-L-cysteine derivatives of D/L-Asp (due to the instability below pH 7). To ensure the accuracy of the method, the validation parameters' specificity, precision, linearity, and LOD were determined. Three dentin samples of premolar teeth, extracted from living individuals (bucco-lingual longitudinal sections of 1 mm thickness), were analyzed and quantitative results are discussed.

  19. Thermoactive β-N-acetylhexosaminidase production by a soil isolate of Penicillium monoverticillium CFR 2 under solid state fermentation: parameter optimization and application for N-acetyl chitooligosaccharides preparation from chitin.

    PubMed

    Suresh, P V; Anil Kumar, P K; Sachindra, N M

    2011-06-01

    Two fungal strains were evaluated for β-N-acetylhexosaminidase production by solid state fermentation using different agro-industrial residues such as commercial wheat bran (CWB) and shrimp shell chitin waste (SSCW), of which Penicillium monoverticillium CFR 2 a local soil isolate showed significantly (P ≤ 0.001) higher β-N-acetylhexosaminidase activity on CWB medium as compared with the activity of Fusarium oxysporum CFR 8. Fermentation parameters such as incubation temperature, incubation time, initial moisture content and inoculum concentration were optimized by statistically designed experiments, using 3**(4-1) fractional factorial design of Response Surface Methodology. The high R(2) (0.9512) observed during validation experiment showed the usefulness of the model. Highest level of enzyme activity (311.84 U/g IDS) was predicted at 75% (w/w) initial moisture content, 26 °C incubation temperature, 168 h incubation time and initial inoculum, at the highest concentration tested (2.95 ml spore suspension/5 g substrate). Statistical optimization yielded a 4.5 fold increase in β-N-acetylhexosaminidase activity. The crude β-N-acetylhexosaminidase showed optimum temperature of 57 ± 1 °C and pH of 3.6 and retained 50% activity after 1 h of incubation at 57 ± 1 °C. SDS-PAGE zymogram revealed crude enzyme was a monomer with an apparent molecular weight ~110 kDa. The crude enzyme formed 6.81 ± 0.03 mM/l of N-acetyl chitooligosaccharides from colloidal chitin in 24 h of incubation. HPLC analysis revealed hydrolysate contained 37.57% N-acetyl chitotriose and 62.43% N-acetyl chitohexose, indicating its potential for specific N-acetyl chitooligosaccharides production.

  20. Conformational distributions of N-acetyl-L-cysteine in aqueous solutions: a combined implicit and explicit solvation treatment of VA and VCD spectra.

    PubMed

    Poopari, Mohammad Reza; Dezhahang, Zahra; Yang, Guochun; Xu, Yunjie

    2012-06-18

    The conformational distributions of N-acetyl-L-cysteine (NALC) in aqueous solutions at several representative pH values are investigated using vibrational absorption (VA), UV/Vis, and vibrational circular dichroism (VCD) spectroscopy, together with DFT and molecular dynamics (MD) simulations. The experimental VA and UV/Vis spectra of NALC in water are obtained under strongly acid, neutral, and strongly basic conditions, as well as the VCD spectrum at pH 7 in D(2)O. Extensive searches are carried out to locate the most stable conformers of the protonated, neutral, deprotonated, and doubly deprotonated NALC species at the B3LYP/6-311++G(d,p) level. The inclusion of the polarizable continuum model (PCM) modifies the geometries and the relative stabilities of the conformers noticeably. The simulated PCM VA spectra show significantly better agreement with the experimental data than the gas-phase ones, thus allowing assignment of the conformational distributions and dominant species under each experimental condition. To further properly account for the discrepancies noted between the experimental and simulated VCD spectra, PCM and the explicit solvent model are utilized. MD simulations are used to aid the modelling of the NALC-(water)(N) clusters. The geometry optimization, harmonic frequency calculations, and VA and VCD intensities are computed for the NALC-(water)(3,4) clusters at the B3LYP/6-311++G(d,p) level without and with the PCM. The inclusion of both explicit and implicit solvation models at the same time provides a decisively better agreement between theory and experiment and therefore conclusive information about the conformational distributions of NALC in water and hydrogen-bonding interactions between NALC and water molecules.

  1. Antioxidant N-acetyl-L-cysteine (NAC) supplementation reduces reactive oxygen species (ROS)-mediated hepatocellular tumor promotion of indole-3-carbinol (I3C) in rats.

    PubMed

    Shimamoto, Keisuke; Hayashi, Hitomi; Taniai, Eriko; Morita, Reiko; Imaoka, Masako; Ishii, Yuji; Suzuki, Kazuhiko; Shibutani, Makoto; Mitsumori, Kunitoshi

    2011-01-01

    Indole-3-carbinol (I3C) has a liver tumor promoting activity in rats, and is also known as a cytochrome p450 1A (CYP1A) inducer. The generation of reactive oxygen species (ROS) resulting from CYP1A induction due to I3C, is probably involved in the tumor promotion. To clarify whether ROS generation contributes to I3C's induction of hepatocellular altered foci, partially hepatectomized rats were fed a diet containing 0.5% of I3C for 8 weeks with or without 0.3% N-acetyl-L-cysteine (NAC), an antioxidant, in their drinking water after N-diethylnitrosamine (DEN) initiation. Immunohistochemical analysis showed that the glutathione-S-transferase placental form (GST-P) positive foci promoted by I3C were suppressed by the administration of NAC. The mRNAs of members of the phase II nuclear factor, erythroid derived 2, like 2 (Nrf2) gene batteries, whose promoter region is called as antioxidant response element (ARE), were down-regulated in the DEN-I3C-NAC group compared to the DEN-I3C group, but Cyp1a1 was not suppressed in the DEN-I3C-NAC group compared to the DEN-I3C group. There was no marked difference in production of microsomal ROS and genomic 8-hydroxy-2'-deoxygunosine (8-OHdG) as an oxidative DNA marker between the DEN-I3C-NAC and DEN-I3C groups, while mapkapk3 and Myc were decreased by the NAC treatment. These results indicate that oxidative stress plays an important role for I3C's tumor promotion, and NAC suppresses induction of hepatocellular altered foci with suppressed cytoplasmic oxidative stress.

  2. N-acetyl-seryl-aspartyl-lysyl-proline prevents cardiac remodeling and dysfunction induced by galectin-3, a mammalian adhesion/growth-regulatory lectin

    PubMed Central

    Liu, Yun-He; D'Ambrosio, Martin; Liao, Tang-dong; Peng, Hongmei; Rhaleb, Nour-Eddine; Sharma, Umesh; André, Sabine; Gabius, Hans-J.; Carretero, Oscar A.

    2009-01-01

    Galectin-3 (Gal-3) is secreted by activated macrophages. In hypertension, Gal-3 is a marker for hypertrophic hearts prone to develop heart failure. Gal-3 infused in pericardial sac leads to cardiac inflammation, remodeling, and dysfunction. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a naturally occurring tetrapeptide, prevents and reverses inflammation and collagen deposition in the heart in hypertension and heart failure postmyocardial infarction. In the present study, we hypothesize that Ac-SDKP prevents Gal-3-induced cardiac inflammation, remodeling, and dysfunction, and these effects are mediated by the transforming growth factor (TGF)-β/Smad3 signaling pathway. Adult male rats were divided into four groups and received the following intrapericardial infusion for 4 wk: 1) vehicle (saline, n = 8); 2) Ac-SDKP (800 μg·kg−1·day−1, n = 8); 3) Gal-3 (12 μg/day, n = 7); and 4) Ac-SDKP + Gal-3 (n = 7). Left ventricular ejection fraction, cardiac output, and transmitral velocity were measured by echocardiography; inflammatory cell infiltration, cardiomyocyte hypertrophy, and collagen deposition in the heart by histological and immunohistochemical staining; and TGF-β expression and Smad3 phosphorylation by Western blot. We found that, in the left ventricle, Gal-3 1) enhanced macrophage and mast cell infiltration, increased cardiac interstitial and perivascular fibrosis, and causes cardiac hypertrophy; 2) increased TGF-β expression and Smad3 phosphorylation; and 3) decreased negative change in pressure over time response to isoproterenol challenge, ratio of early left ventricular filling phase to atrial contraction phase, and left ventricular ejection fraction. Ac-SDKP partially or completely prevented these effects. We conclude that Ac-SDKP prevents Gal-3-induced cardiac inflammation, fibrosis, hypertrophy, and dysfunction, possibly via inhibition of the TGF-β/Smad3 signaling pathway. PMID:19098114

  3. N-acetyl-beta-D-glucopyranosylamine: a potent T-state inhibitor of glycogen phosphorylase. A comparison with alpha-D-glucose.

    PubMed Central

    Oikonomakos, N. G.; Kontou, M.; Zographos, S. E.; Watson, K. A.; Johnson, L. N.; Bichard, C. J.; Fleet, G. W.; Acharya, K. R.

    1995-01-01

    Structure-based drug design has led to the discovery of a number of glucose analogue inhibitors of glycogen phosphorylase that have an increased affinity compared to alpha-D-glucose (Ki = 1.7 mM). The best inhibitor in the class of N-acyl derivatives of beta-D-glucopyranosylamine, N-acetyl-beta-D-glucopyranosylamine (1-GlcNAc), has been characterized by kinetic, ultracentrifugation, and crystallographic studies. 1-GlcNAc acts as a competitive inhibitor for both the b (Ki = 32 microM) and the a (Ki = 35 microM) forms of the enzyme with respect to glucose 1-phosphate and in synergism with caffeine, mimicking the binding of glucose. Sedimentation velocity experiments demonstrated that 1-GlcNAc was able to induce dissociation of tetrameric phosphorylase a and stabilization of the dimeric T-state conformation. Co-crystals of the phosphorylase b-1-GlcNAc-IMP complex were grown in space group P4(3)2(1)2, with native-like unit cell dimensions, and the complex structure has been refined to give a crystallographic R factor of 18.1%, for data between 8 and 2.3 A resolution. 1-GlcNAc binds tightly at the catalytic site of T-state phosphorylase b at approximately the same position as that of alpha-D-glucose. The ligand can be accommodated in the catalytic site with very little change in the protein structure and stabilizes the T-state conformation of the 280s loop by making several favorable contacts to Asn 284 of this loop. Structural comparisons show that the T-state phosphorylase b-1-GlcNAc-IMP complex structure is overall similar to the T-state phosphorylase b-alpha-D-glucose complex structure. The structure of the 1-GlcNAc complex provides a rational for the biochemical properties of the inhibitor. PMID:8580837

  4. Effect of N-acetyl cysteine and glycine supplementation on growth performance, glutathione synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus.

    PubMed

    Xie, Shiwei; Zhou, Weiwen; Tian, Lixia; Niu, Jin; Liu, Yongjian

    2016-08-01

    An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione (GSH) synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus. Four practical diets were formulated, control, control +0.2% NAC, control +0.5% glycine, control +0.2% NAC +0.5% glycine. Each diet was randomly assigned to quadruplicate groups of 30 fish (approximately 9.5 g). The weight gain and specific growth rate were significantly increased with the supplementation of NAC and glycine. While they had no effect on feed efficiency feed intake and survival. Glutathion peroxidase (GPx) was increased by NAC and γ-glutamine cysteine synthase (γ-GCS) in plasma were increased by glycine. After the feeding trail, fish were challenged by Streptococcus iniae, fish fed the diet supplemented with NAC obtained significantly higher survival rate after 72 h challenge test. NAC also decreased malonaldehyde (MDA) in liver, increased glutathione S-transferase (GST) activity in plasma, up-regulated mRNA expression of Superoxide dismutase (SOD) and GPx in liver and headkidney. Dietary supplementation of glycine increased the anti-oxidative ability of tilapia through increase anti-oxidative enzyme activity (SOD, glutathione reductase, myeloperoxidase) and up-regulate anti-oxidative gene expression (SOD). Immune ability only enhanced by the supplementation of NAC through increased interleukin-1β (IL-1β) mRNA expression. These results clearly indicated that the supplementation of NAC and glycine can significantly improve the growth performance of tilapia, and NAC also enhance the anti-oxidative and immune capacity of tilapia, glycine could only enhance the anti-oxidative ability.

  5. L-lactate dehydrogenase and N-acetyl-beta-D-glucosaminidase activities in bovine milk as indicators of non-specific mastitis.

    PubMed

    Chagunda, Mizeck Gg; Larsen, Torben; Bjerring, Martin; Ingvartsen, Klaus L

    2006-11-01

    Systematic factors affecting the activities of L-lactate dehydrogenase (LDH) and N-acetyl-beta-D-glucosaminidase (NAGase) and somatic cell count (SCC), the association between the activities of LDH and NAGase and SCC with respect to udder health status, and the ability of LDH and NAGase to classify cows in udder health categories for early detection of mastitis were studied. A dataset of records from 74 Danish Holstein, 76 Danish Red and 47 Jersey cows on one research farm was used. Cows were grouped into healthy and clinically mastitic. A healthy cow was defined as having no veterinary treatment and SCC<100,000 cells/ml. A clinically infected cow was one receiving veterinary treatment after showing clinical signs of mastitis and SCC >800,000 cells/ml. Breed, month of production, and days in milk significantly influenced (P<0.001) LDH activity, NAGase activity and SCC in both healthy and clinically mastitic cows. In healthy cows, LDH activity, NAGase activity and SCC started at a high level immediately after calving and decreased to low levels approximately 30-40 d post partum. All the three parameters increased due to clinical mastitis. NAGase activity had numerically higher variation in healthy cows than in clinically mastitic cows (CV=56.2% v. CV=53.5%). The relationship between LDH activity and SCC was stronger in milk from clinically mastitic than from healthy cows (r=0.76 v. r=0.48 and r=0.67 v. r=0.44 for correlation of observed values and residuals, respectively). LDH activity had higher sensitivity than NAGase activity (73-95% v. 35-77%) while specificities were in a similar range (92-99%). Further, sensitivities for LDH activity were more robust to changes in the threshold value than those for NAGase activity. Opportunities for automated, in-line real-time mastitis detection are discussed.

  6. Arylamine N-acetyl Transferase (NAT) in the blue secretion of Telescopium telescopium: xenobiotic metabolizing enzyme as a biomarker for detection of environmental pollution.

    PubMed

    Gorain, Bapi; Chakraborty, Sumon; Pal, Murari Mohan; Sarkar, Ratul; Samanta, Samir Kumar; Karmakar, Sanmoy; Sen, Tuhinadri

    2014-01-01

    Telescopium telescopium, a marine mollusc collected from Sundarban mangrove, belongs to the largest mollusca phylum in the world and exudes a blue secretion when stimulated mechanically. The blue secretion was found to metabolize (preferentially) para-amino benzoic acid, a substrate for N-acetyl transferase (NAT), thereby indicating acetyl transferase like activity of the secretion. Attempts were also made to characterise bioactive fraction of the blue secretion and to further use this as a biomarker for monitoring of marine pollution. NAT like enzyme from marine mollusc is a potential candidate for detoxification of different harmful chemicals. A partially purified extract of blue secretion was obtained by fractional precipitation with (NH4)2SO4. From different fractions obtained by precipitation, the 0-30% fraction (30S) displayed NAT like activity (using para amino benzoic acid as a substrate with para nitrophenyl phosphate or acetyl coenzyme A as acetyl group donors). Maximum NAT like enzyme activity was attained at 25°C and at a pH of 6. The enzyme activity was found to be inhibited by 5 mM phenyl methyl sulfonyl fluoride. The divalent metal ions reduced NAT like activity of 30S. Moreover, Cu(2+) and Zn(2+) (at concentration of 1 mM) completely inhibited NAT activity. The thermal stability and bench-top stability studies were performed and it was found that the enzyme was stable at room temperature for more than 24 hours. Results from the present study further indicate that heavy metal content in blue secretion gradually decreased from pre-monsoon to post-monsoon season, which also corresponded to the change in NAT like activity. Therefore, this article stresses the importance of biomarker research for monitoring pollution.

  7. N-Acetyl Cysteine Attenuated the Deleterious Effects of Advanced Glycation End-Products on the Kidney of Non-Diabetic Rats.

    PubMed

    Thieme, Karina; Da Silva, Karolline S; Fabre, Nelly T; Catanozi, Sergio; Monteiro, Maria Beatriz; Santos-Bezerra, Daniele Pereira; Costa-Pessoa, Juliana Martins; Oliveira-Souza, Maria; Machado, Ubiratan F; Passarelli, Marisa; Correa-Giannella, Maria Lucia

    2016-01-01

    To assess the renal effects of chronic exposure to advanced glycation end-products (AGEs) in the absence of diabetes and the potential impact of concomitant treatment with the antioxidant N-acetyl cysteine (NAC). Wistar rats received intraperitoneally 20 mg/kg/day of albumin modified (AlbAGE) or not (AlbC) by advanced glycation for 12 weeks and oral NAC (600mg/L; AlbAGE+NAC and AlbC+NAC, respectively). Biochemical, urinary and renal morphological analyses; carboxymethyl-lysine (CML, an AGE), CD68 (macrophage infiltration), and 4-hydroxynonenal (4-HNE, marker of oxidative stress) immunostaining; intrarenal mRNA expression of genes belonging to pathways related to AGEs (Ager, Ddost, Nfkb1), renin-angiotensin system (Agt, Ren, Ace), fibrosis (Tgfb1, Col4a1), oxidative stress (Nox4, Txnip), and apoptosis (Bax, Bcl2); and reactive oxidative species (ROS) content were performed. AlbAGE significantly increased urine protein-to-creatinine ratio; glomerular area; renal CML content and macrophage infiltration; expression of Ager, Nfkb1, Agt, Ren, Tgfb1, Col4a1, Txnip, Bax/Bcl2 ratio; and 4-HNE and ROS contents. Some of these effects were attenuated by NAC concomitant treatment. Because AGEs are highly consumed in modern diets and implicated in the progression of different kidney diseases, NAC could be a therapeutic intervention to decrease renal damage, considering that long-term restriction of dietary AGEs is difficult to achieve in practice. © 2016 The Author(s) Published by S. Karger AG, Basel.

  8. Protection of rats against 3-butene-1,2-diol-induced hepatotoxicity and hypoglycemia by N-acetyl-L-cysteine

    SciTech Connect

    Sprague, Christopher L.; Elfarra, Adnan A. . E-mail: elfarra@svm.vetmed.wisc.edu

    2005-09-15

    3-Butene-1,2-diol (BDD), an allylic alcohol and major metabolite of 1,3-butadiene, has previously been shown to cause hepatotoxicity and hypoglycemia in male Sprague-Dawley rats, but the mechanisms of toxicity were unclear. In this study, rats were administered BDD (250 mg/kg) or saline, ip, and serum insulin levels, hepatic lactate levels, and hepatic cellular and mitochondrial GSH, GSSG, ATP, and ADP levels were measured 1 or 4 h after treatment. The results show that serum insulin levels were not causing the hypoglycemia and that the hypoglycemia was not caused by an enhancement of the metabolism of pyruvate to lactate because hepatic lactate levels were either similar (1 h) or lower (4 h) than controls. However, both hepatic cellular and mitochondrial GSH and GSSG levels were severely depleted 1 and 4 h after treatment and the mitochondrial ATP/ADP ratio was also lowered 4 h after treatment relative to controls. Because these results suggested a role for hepatic cellular and mitochondrial GSH in BDD toxicity, additional rats were administered N-acetyl-L-cysteine (NAC; 200 mg/kg) 15 min after BDD administration. NAC treatment partially prevented depletion of hepatic cellular and mitochondrial GSH and preserved the mitochondrial ATP/ADP ratio. NAC also prevented the severe depletion of serum glucose concentration and the elevation of serum alanine aminotransferase activity after BDD treatment without affecting the plasma concentration of BDD. Thus, depletion of hepatic cellular and mitochondrial GSH followed by the decrease in the mitochondrial ATP/ADP ratio was likely contributing to the mechanisms of hepatotoxicity and hypoglycemia in the rat.

  9. Characterization of cell death induced by ethacrynic acid in a human colon cancer cell line DLD-1 and suppression by N-acetyl-L-cysteine.

    PubMed

    Aizawa, Shu; Ookawa, Keizou; Kudo, Toshihiro; Asano, Junpei; Hayakari, Makoto; Tsuchida, Shigeki

    2003-10-01

    Since ethacrynic acid (EA), an SH modifier as well as glutathione S-transferase (GST) inhibitor, has been suggested to induce apoptosis in some cell lines, its effects on a human colon cancer cell line DLD-1 were examined. EA enhanced cell proliferation at 20-40 microM, while it caused cell death at 60-100 microM. Caspase inhibitors did not block cell death and DNA ladder formation was not detected. Poly(ADP-ribose) polymerase, however, was cleaved into an 82-kDa fragment, different from an 85-kDa fragment that is specific for apoptosisis. The 82-kDa fragment was not recognized by antibody against PARP fragment cleaved by caspase 3. N-Acetyl-L-cysteine (NAC) completely inhibited EA-induced cell death, but 3(2)-t-butyl-4-hydroxyanisole or pyrrolidinedithiocarbamate ammonium salt did not. Glutathione (GSH) levels were dose-dependently increased in cells treated with EA and this increase was hardly affected by NAC addition. Mitogen-activated protein kinase (MAPK) kinase (MEK) 1, extracellular signal-regulated kinase (ERK) 1 and GST P1-1 were increased in cells treated with 25-75 microM EA, while c-Jun N-terminal kinase (JNK) 1 and p38 MAPK were markedly decreased by 100 microM EA. NAC repressed EA-induced alterations in these MAPKs and GST P1-1. p38 MAPK inhibitors, SB203580 and FR167653, dose-dependently enhanced EA-induced cell death. An MEK inhibitor, U0126, did not affect EA-induced cell death. These studies revealed that EA induced cell death concomitantly with a novel PARP fragmentation, but without DNA fragmentation. p38 MAPK was suggested to play an inhibitory role in EA-induced cell death.

  10. Golgi UDP-GlcNAc:polypeptide O-α-N-Acetyl-d-glucosaminyltransferase 2 (TcOGNT2) regulates trypomastigote production and function in Trypanosoma cruzi.

    PubMed

    Koeller, Carolina M; van der Wel, Hanke; Feasley, Christa L; Abreu, Fernanda; da Rocha, Juliana Dutra Barbosa; Montalvão, Fabrício; Fampa, Patrícia; Dos Reis, Flávia C G; Atella, Georgia C; Souto-Padrón, Thaís; West, Christopher M; Heise, Norton

    2014-10-01

    All life cycle stages of the protozoan parasite Trypanosoma cruzi are enveloped by mucin-like glycoproteins which, despite major changes in their polypeptide cores, are extensively and similarly O-glycosylated. O-Glycan biosynthesis is initiated by the addition of αGlcNAc to Thr in a reaction catalyzed by Golgi UDP-GlcNAc:polypeptide O-α-N-acetyl-d-glucosaminyltransferases (ppαGlcNAcTs), which are encoded by TcOGNT1 and TcOGNT2. We now directly show that TcOGNT2 is associated with the Golgi apparatus of the epimastigote stage and is markedly downregulated in both differentiated metacyclic trypomastigotes (MCTs) and cell culture-derived trypomastigotes (TCTs). The significance of downregulation was examined by forced continued expression of TcOGNT2, which resulted in a substantial increase of TcOGNT2 protein levels but only modestly increased ppαGlcNAcT activity in extracts and altered cell surface glycosylation in TCTs. Constitutive TcOGNT2 overexpression had no discernible effect on proliferating epimastigotes but negatively affected production of both types of trypomastigotes. MCTs differentiated from epimastigotes at a low frequency, though they were apparently normal based on morphological and biochemical criteria. However, these MCTs exhibited an impaired ability to produce amastigotes and TCTs in cell culture monolayers, most likely due to a reduced infection frequency. Remarkably, inhibition of MCT production did not depend on TcOGNT2 catalytic activity, whereas TCT production was inhibited only by active TcOGNT2. These findings indicate that TcOGNT2 downregulation is important for proper differentiation of MCTs and functioning of TCTs and that TcOGNT2 regulates these functions by using both catalytic and noncatalytic mechanisms.

  11. Atorvastatin acts synergistically with N-acetyl cysteine to provide therapeutic advantage against Fas-activated erythrocyte apoptosis during chronic arsenic exposure in rats

    SciTech Connect

    Biswas, Debabrata; Sen, Gargi; Sarkar, Avik; Biswas, Tuli

    2011-01-01

    Arsenic is an environmental toxicant that reduces the lifespan of circulating erythrocytes during chronic exposure. Our previous studies had indicated involvement of hypercholesterolemia and reactive oxygen species (ROS) in arsenic-induced apoptotic death of erythrocytes. In this study, we have shown an effective recovery from arsenic-induced death signaling in erythrocytes in response to treatment with atorvastatin (ATV) and N-acetyl cysteine (NAC) in rats. Our results emphasized on the importance of cholesterol in the promotion of ROS-mediated Fas signaling in red cells. Arsenic-induced activation of caspase 3 was associated with phosphatidylserine exposure on the cell surface and microvesiculation of erythrocyte membrane. Administration of NAC in combination with ATV, proved to be more effective than either of the drugs alone towards the rectification of arsenic-mediated disorganization of membrane structural integrity, and this could be linked with decreased ROS accumulation through reduced glutathione (GSH) repletion along with cholesterol depletion. Moreover, activation of caspase 3 was capable of promoting aggregation of band 3 with subsequent binding of autologous IgG and opsonization by C3b that led to phagocytosis of the exposed cells by the macrophages. NAC-ATV treatment successfully amended these events and restored lifespan of erythrocytes from the exposed animals almost to the control level. This work helped us to identify intracellular membrane cholesterol enrichment and GSH depletion as the key regulatory points in arsenic-mediated erythrocyte destruction and suggested a therapeutic strategy against Fas-activated cell death related to enhanced cholesterol and accumulation of ROS.

  12. Developmental cell death in the liver and newborn lethality of Ku86 deficient mice suppressed by antioxidant N-acetyl-cysteine.

    PubMed

    Reliene, Ramune; Goad, Marry E P; Schiestl, Robert H

    2006-11-08

    Repair of DNA double-strand breaks (DSBs) is essential for genome integrity and cell survival. Ku86 is involved in the repair of DNA DSBs by non-homologous end joining (NHEJ). Mice deficient in Ku86 show growth retardation, dwarfism, premature aging, and immunodeficiency. In this study, we observed severely compromised survival of Ku86(-/-) mice, such that most Ku86(-/-) mice died within the first postnatal weeks and only 1.5% of the expected 25% from heterozygous crosses survived for 1 month. Since post-mortem analysis was not possible due to parental cannibalism, histopathological examination was performed on Ku86(-/-) fetuses to assess possible causes of newborn death. Eighty percent and 75% of Ku86(-/-) fetuses exhibited apoptosis and necrosis in the liver, while only 20% and 10% of Ku86(+/+) littermates had apoptosis and necrosis, respectively. In addition, the severity of liver damage was significantly higher in Ku86(-/-) fetuses. Developmental liver damage may have led to postnatal lethality because the fetal liver with pre-existing injury may not be able to undergo transformation from a lymphohematopoietic to an indispensable metabolic organ. Free radicals can cause chromosomal breaks and lead to cell death. We postulated that endogenous oxidative stress might be involved in the resulting liver damage and animal lethality in Ku86(-/-) mice deficient in DNA DSB repair. This hypothesis was tested by treating Ku86(-/-) mice with the well known free radical scavenger, thiol antioxidant N-acetyl-cysteine (NAC), during embryonic development. We found that a significantly higher percentage, 7.7% of NAC treated Ku86(-/-) offspring versus 1.5% untreated Ku86(-/-) mice were alive at 1 month of age. In addition, the incidence of liver necrosis decreased by 21% and the severity of necrosis significantly reduced. Thus, Ku86 deficiency results in severe developmental liver damage and newborn lethality associated with oxidative stress.

  13. The protein BpsB is a poly-β-1,6-N-acetyl-D-glucosamine deacetylase required for biofilm formation in Bordetella bronchiseptica.

    PubMed

    Little, Dustin J; Milek, Sonja; Bamford, Natalie C; Ganguly, Tridib; DiFrancesco, Benjamin R; Nitz, Mark; Deora, Rajendar; Howell, P Lynne

    2015-09-11

    Bordetella pertussis and Bordetella bronchiseptica are the causative agents of whooping cough in humans and a variety of respiratory diseases in animals, respectively. Bordetella species produce an exopolysaccharide, known as the Bordetella polysaccharide (Bps), which is encoded by the bpsABCD operon. Bps is required for Bordetella biofilm formation, colonization of the respiratory tract, and confers protection from complement-mediated killing. In this report, we have investigated the role of BpsB in the biosynthesis of Bps and biofilm formation by B. bronchiseptica. BpsB is a two-domain protein that localizes to the periplasm and outer membrane. BpsB displays metal- and length-dependent deacetylation on poly-β-1,6-N-acetyl-d-glucosamine (PNAG) oligomers, supporting previous immunogenic data that suggests Bps is a PNAG polymer. BpsB can use a variety of divalent metal cations for deacetylase activity and showed highest activity in the presence of Ni(2+) and Co(2+). The structure of the BpsB deacetylase domain is similar to the PNAG deacetylases PgaB and IcaB and contains the same circularly permuted family four carbohydrate esterase motifs. Unlike PgaB from Escherichia coli, BpsB is not required for polymer export and has unique structural differences that allow the N-terminal deacetylase domain to be active when purified in isolation from the C-terminal domain. Our enzymatic characterizations highlight the importance of conserved active site residues in PNAG deacetylation and demonstrate that the C-terminal domain is required for maximal deacetylation of longer PNAG oligomers. Furthermore, we show that BpsB is critical for the formation and complex architecture of B. bronchiseptica biofilms.

  14. Activity of N-acetyl-beta-D-hexosaminidase (HEX) and its isoenzymes A and B in human milk during the first 3 months of breastfeeding.

    PubMed

    Dudzik, D; Knas, M; Gocal, M; Borzym-Kluczyk, M; Szajda, S D; Knaś-Karaszewska, K; Tomaszewski, J; Zwierz, K

    2008-01-01

    Milk contains free and bound oligo- and heteropolisaccharides, which protect newborns against pathogens and have nutritional value. N-acetyl-beta-D-hexosaminidase (HEX), the most active lysosomal exoglycosidase, modify and degrade oligo- and heteropolysaccharides. The objective of our study was to determine HEX activity and isoenzymes A and B in the progression of lactation. Human milk samples were collected from 51 women on the 3rd, 21st and 100th day postpartum. Enzymatic activity was determined the Zwierz et al method modified by Marciniak et al. Protein and lactose concentrations were determined by a MilkoScan 4000 apparatus. The total HEX activity decreased by the 21st day in comparison to the 3rd day, and increased by the 100th day as compared to the 21st day. HEX A activity decreased by the 21st and the 100th day as compared to the 3rd day. HEX B activity decreased by 21st day and has the tendency to decrease by the 100th day as compared to the 3rd day. Protein concentration decreased and the lactose concentration increased in milk taken on the 21st day in comparison to concentration of protein and lactose on the 3rd day. HEX and its isoenzymes' activity significantly correlate with the progression of lactation. At the beginning of lactation, HEX A activity, which releases hexosamines from acidic oligosaccharides, dominates; later, HEX B releases hexosamines from neutral oligosaccharides. To better understand the degradation of human milk oligosaccharides, it would be useful to investigate and document their detailed structures and evaluate the activity of other exoglycosidases' activity in human breast milk over the course of lactation.

  15. [Concentration of thyroid stimulating hormone and activity of N-acetyl-beta-D-hexosaminidase and its isoenzymes, in serum of patients with thyroid cancer].

    PubMed

    Zwierz, Piotr; Szajda, Sławomir D; Snarska, Jadwiga; Supronowicz, Zbigniew B; Zawadzki, Paweł; Zwierz, Krzysztof; Kamińsk, Fabian

    2006-11-01

    Thyroid cancer consists 1% of all malignant neoplasms. It is not known interrelationship between concentration of TSH in blood serum and condition of thyroid cancer. Thyroid cancer is difficult for diagnosis and differentiation. Therefore it is necessary to search for biochemical markers helpful in diagnostics of thyroid cancer. Significant increase in activity of N-acetyl-beta-D-hexosaminidase and its isoenzymes A and B in serum of patients with neoplasms of kidney and pancreas suggest approporiateness of evaluation of HEX and its isoenzymes in diagnostics of thyroid cancer. of the study--evaluation of TSH concentration and activity of HEX and its isoenzymes A and B, in serum of patients with thyroid cancer. Blood was taken from 7 patients with thyroid cancer (6 men and 1 woman). Control consisted of 7 healthy men. In blood serum concentration of TSH was determined with immunoenzymatic method on analyzer Axsym of Abbott and expressed in microU/mL. The activity of HEX and its isoenzymes A and B was determined by method of Chatterjee et al., as modified by Zwierz et.al. Determination of HEX was performed on microplate reader ELX800 BIO-TEK. Activity of HEX, HEX A and B was expressed in pKat/mL, and specific activity in pKat/mg protein). Protein was determined by biuret method and results were expressed in mg/mL. Concentration of HEX A activity in serum of thyroid cancer patients is significantly higherin comparison to healthymen (p = 0.0191). Also specific activity of HEX A in serum of thyroid cancer patients is significantly higher in comparison to healthy men (p = 0.0393). 1. Determination of TSH concentration in serum of thyroid cancer before the operation may confirm euthyreosis. 2. Determination of HEX A activity in serum may be helpful in diagnostics of thyroid cancer.

  16. N-acetyl-beta-D-hexosaminidase and its isoenzymes A and B in blood serum and urine, as a potential colon cancer markers.

    PubMed

    Szajda, Sławomir Dariusz; Borzym-Kluczyk, Małgorzata; Snarska, Jadwiga; Puchalski, Zbigniew; Zwierz, Krzysztof

    2009-01-01

    Evaluation of N-acetyl-beta-D-hexosaminidase (HEX), and its isoenzymes A (HEX A) and B (HEX B) activity in blood serum and urine as potential markers of colorectal cancer. The study was performed in blood serum and urine of 32 patients with adenocarcinoma, 6 with adenocarcinoma mucinosum of the colon, and 20 healthy people. The activity of HEX, HEX A and HEX B was determined in blood serum and urine by spectrophotometric method of Marciniak et al. The concentration of CEA was determined in blood serum by immunoenzymatic method (MEIA). The concentration of protein was assessed by the Lowry method, whereas the concentration of creatinine in urine by the Jaffe method (without deproteinization). A significant increase in the concentration of HEX, HEX A and HEX B activity was proved in serum and urine of patients with colon adenocarcinoma. In patients with colon adenocarcinoma mucinosum, the higher activity of HEX was revealed in blood serum compared to healthy people, and the significantly higher activity of HEX and HEX B expressed as pKat/mg of creatinine, was found in urine. We observe a significant increase in the activity of HEX, HEX A and HEX B expressed in pKat/mg of creatinine was found in urine of patients bearing tumor of diameter 6.0-7.0 cm in comparison to patients with tumor of diameter 4.0-5.0 cm. The present study results suggest that determination of HEX, HEX A and HEX B activity in blood serum and urine may be used to detect colon cancer in its early stages. However, the use of HEX, HEX A and HEX B activity in oncological diagnostics requires further studies on a larger group of patients.

  17. Efficacy of intravenous administration of hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine for prevention or treatment of osteoarthritis in horses.

    PubMed

    Frisbie, David D; McIlwraith, C Wayne; Kawcak, Christopher E; Werpy, Natasha M

    2016-10-01

    OBJECTIVE To evaluate the efficacy of IV administration of a product containing hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine for prevention or treatment of osteoarthritis in horses. ANIMALS 32 healthy 2- to 5-year-old horses. PROCEDURES The study involved 2 portions. To evaluate prophylactic efficacy of the test product, horses received 5 mL of the product (n = 8) or saline (0.9% NaCl) solution (8; placebo) IV every fifth day, starting on day 0 (when osteoarthritis was induced in the middle carpal joint of 1 forelimb) and ending on day 70. To evaluate treatment efficacy, horses received either the product or placebo (n = 8/treatment) on days 16, 23, 30, 37, and 44 after osteoarthritis induction. Clinical, diagnostic imaging, synovial fluid, gross anatomic, and histologic evaluations and other tests were performed. Results of each study portion were compared between treatment groups. RESULTS Limb flexion and radiographic findings were significantly worse for horses that received the test product in the prophylactic efficacy portion than for placebo-treated horses or product-treated horses in the treatment efficacy portion. In the prophylactic efficacy portion, significantly less articular cartilage erosion was identified in product-treated versus placebo-treated horses. In the treatment efficacy portion, joints of product-treated horses had a greater degree of bone edema identified via MRI than did joints of placebo-treated horses but fewer microscopic articular cartilage abnormalities. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that caution should be used when administering the evaluated product IV to horses, particularly when administering it prophylactically, as it may have no benefit or may even cause harm.

  18. N-acetyl-seryl-aspartyl-lysyl-proline prevents cardiac remodeling and dysfunction induced by galectin-3, a mammalian adhesion/growth-regulatory lectin.

    PubMed

    Liu, Yun-He; D'Ambrosio, Martin; Liao, Tang-dong; Peng, Hongmei; Rhaleb, Nour-Eddine; Sharma, Umesh; André, Sabine; Gabius, Hans-J; Carretero, Oscar A

    2009-02-01

    Galectin-3 (Gal-3) is secreted by activated macrophages. In hypertension, Gal-3 is a marker for hypertrophic hearts prone to develop heart failure. Gal-3 infused in pericardial sac leads to cardiac inflammation, remodeling, and dysfunction. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a naturally occurring tetrapeptide, prevents and reverses inflammation and collagen deposition in the heart in hypertension and heart failure postmyocardial infarction. In the present study, we hypothesize that Ac-SDKP prevents Gal-3-induced cardiac inflammation, remodeling, and dysfunction, and these effects are mediated by the transforming growth factor (TGF)-beta/Smad3 signaling pathway. Adult male rats were divided into four groups and received the following intrapericardial infusion for 4 wk: 1) vehicle (saline, n = 8); 2) Ac-SDKP (800 microg x kg(-1) x day(-1), n = 8); 3) Gal-3 (12 microg/day, n = 7); and 4) Ac-SDKP + Gal-3 (n = 7). Left ventricular ejection fraction, cardiac output, and transmitral velocity were measured by echocardiography; inflammatory cell infiltration, cardiomyocyte hypertrophy, and collagen deposition in the heart by histological and immunohistochemical staining; and TGF-beta expression and Smad3 phosphorylation by Western blot. We found that, in the left ventricle, Gal-3 1) enhanced macrophage and mast cell infiltration, increased cardiac interstitial and perivascular fibrosis, and causes cardiac hypertrophy; 2) increased TGF-beta expression and Smad3 phosphorylation; and 3) decreased negative change in pressure over time response to isoproterenol challenge, ratio of early left ventricular filling phase to atrial contraction phase, and left ventricular ejection fraction. Ac-SDKP partially or completely prevented these effects. We conclude that Ac-SDKP prevents Gal-3-induced cardiac inflammation, fibrosis, hypertrophy, and dysfunction, possibly via inhibition of the TGF-beta/Smad3 signaling pathway.

  19. Temperature study of indole, tryptophan and N-acetyl-L-tryptophanamide (NATA) triplet-state quenching by iodide in aqueous solution.

    PubMed

    Kowalska-Baron, Agnieszka; Gałęcki, Krystian; Wysocki, Stanisław

    2013-07-01

    In this study, the temperature dependence of the measured phosphorescence lifetimes of aqueous indole, tryptophan and N-acetyl-L-tryptophanamide (NATA) between 6 and 55 °C in the absence and in the presence of iodide, a suitable intersystem crossing enhancer, has been determined. The obtained results suggest the existence of one process for the temperature-dependent, non-radiative deactivation of triplet states of the aqueous indoles in the absence of iodide. This process may be associated with the high sensitivity of indole triplet state lifetime to the subtle changes in the local viscosity of the surrounding aqueous environment or may be attributed to diffusional quenching by solvent molecules and/or by possible impurities present in water. However, the steep decrease in the measured phosphorescence lifetimes of indole and tryptophan with temperature suggests that diffusion-mediated quenching processes are not prevailing. Upon increasing concentration of iodide (up to 0.1 M), the obtained Arrhenius plots for the deactivation rate (1/τph) of the triplet states of the studied indoles were linear, which provided strong support for the hypothesis of the existence of one temperature dependent non-radiative process for the de-excitation of indoles triplet state. Our results showed that this process is attributed to the diffusion-controlled solute-quenching by iodide and, most probably, proceeds via reversibly formed exciplex. At concentration of iodide higher than 0.1M highly curved Arrhenius plots were obtained, which may indicate a change in the rate determining step with a change in temperature. This change most probably is associated with a transition from diffusion-controlled exciplex formation followed by rate-determining exciplex deactivation at high temperature.

  20. Biodegradable poly(lactic-co-glycolic acid) microspheres loaded with S-nitroso-N-acetyl-D-penicillamine for controlled nitric oxide delivery.

    PubMed

    Lautner, Gergely; Meyerhoff, Mark E; Schwendeman, Steven P

    2016-03-10

    Nitric oxide (NO) is a fascinating and important endogenous free-radical gas with potent antimicrobial, vasodilating, smooth muscle relaxant, and growth factor stimulating effects. However, its wider biomedical applicability is hindered by its cumbersome administration, since NO is unstable especially in biological environments. In this work, to ultimately develop site-specific controlled release vehicles for NO, the NO donor S-nitroso-N-acetyl-D-penicillamine (SNAP) was encapsulated within poly(lactic-co-glycolic acid) 50:50 (PLGA) microspheres by using a solid-in-oil-in-water emulsion solvent evaporation method. The highest payload was 0.56(±0.01) μmol SNAP/mg microspheres. The in vitro release kinetics of the donor were controlled by the bioerosion of the PLGA microspheres. By using an uncapped PLGA (Mw=24,000-38,000) SNAP was slowly released for over 10days, whereas by using the ester capped PLGA (Mw=38,000-54,000) the release lasted for over 4weeks. The presence of copper ions and/or ascorbate in solution was necessary to efficiently decompose the released NO donor and obtain sustained NO release. It was also demonstrated that light can be used to induce rapid NO release from the microspheres over several hours. SNAP exhibited excellent storage stability when encapsulated in the PLGA microspheres. These new microsphere formulations may be useful for site-specific administration and treatment of pathologies associated with dysfunction in endogenous NO production, e.g. treatment of diabetic wounds, or in diseases involving other biological functions of NO including vasodilation, antimicrobial, anticancer, and neurotransmission.

  1. The Protein BpsB Is a Poly-β-1,6-N-acetyl-d-glucosamine Deacetylase Required for Biofilm Formation in Bordetella bronchiseptica*

    PubMed Central

    Little, Dustin J.; Milek, Sonja; Bamford, Natalie C.; Ganguly, Tridib; DiFrancesco, Benjamin R.; Nitz, Mark; Deora, Rajendar; Howell, P. Lynne

    2015-01-01

    Bordetella pertussis and Bordetella bronchiseptica are the causative agents of whooping cough in humans and a variety of respiratory diseases in animals, respectively. Bordetella species produce an exopolysaccharide, known as the Bordetella polysaccharide (Bps), which is encoded by the bpsABCD operon. Bps is required for Bordetella biofilm formation, colonization of the respiratory tract, and confers protection from complement-mediated killing. In this report, we have investigated the role of BpsB in the biosynthesis of Bps and biofilm formation by B. bronchiseptica. BpsB is a two-domain protein that localizes to the periplasm and outer membrane. BpsB displays metal- and length-dependent deacetylation on poly-β-1,6-N-acetyl-d-glucosamine (PNAG) oligomers, supporting previous immunogenic data that suggests Bps is a PNAG polymer. BpsB can use a variety of divalent metal cations for deacetylase activity and showed highest activity in the presence of Ni2+ and Co2+. The structure of the BpsB deacetylase domain is similar to the PNAG deacetylases PgaB and IcaB and contains the same circularly permuted family four carbohydrate esterase motifs. Unlike PgaB from Escherichia coli, BpsB is not required for polymer export and has unique structural differences that allow the N-terminal deacetylase domain to be active when purified in isolation from the C-terminal domain. Our enzymatic characterizations highlight the importance of conserved active site residues in PNAG deacetylation and demonstrate that the C-terminal domain is required for maximal deacetylation of longer PNAG oligomers. Furthermore, we show that BpsB is critical for the formation and complex architecture of B. bronchiseptica biofilms. PMID:26203190

  2. N-acetyl-L-cysteine protects against cadmium-induced neuronal apoptosis by inhibiting ROS-dependent activation of Akt/mTOR pathway in mouse brain

    PubMed Central

    Chen, Sujuan; Ren, Qian; Zhang, Jinfei; Ye, Yangjing; Zhang, Zhen; Xu, Yijiao; Guo, Min; Ji, Haiyan; Xu, Chong; Gu, Chenjian; Gao, Wei; Huang, Shile; Chen, Long

    2014-01-01

    Aims This study explores the neuroprotective effects and mechanisms of N-acetyl-L-cysteine (NAC) in mice exposed to cadmium (Cd). Methods NAC (150 mg/kg) was intraperitoneally administered to mice exposed to Cd (10-50 mg/L) in drinking water for 6 weeks. The changes of cell damage and death, reactive oxygen species (ROS), antioxidant enzymes, as well as Akt/mammalian target of rapamycin (mTOR) signaling pathway in brain neurons were assessed. To verify the role of mTOR activation in Cd-induced neurotoxicity, mice also received a subacute regimen of intraperitoneally administered Cd (1 mg/kg) with/without rapamycin (7.5 mg/kg) for 11 days. Results Chronic exposure of mice to Cd induced brain damage or neuronal cell death, due to ROS induction. Co-administration of NAC significantly reduced Cd levels in the plasma and brain of the animals. NAC prevented Cd-induced ROS and significantly attenuated Cd-induced brain damage or neuronal cell death. The protective effect of NAC was mediated, at least partially, by elevating the activities of Cu/Zn-superoxide dismutase, catalase and glutathione peroxidase, as well as the level of glutathione in the brain. Furthermore, Cd-induced activation of Akt/mTOR pathway in the brain was also inhibited by NAC. Rapamycin in vitro and in vivo protected against Cd-induced neurotoxicity. Conclusions NAC protects against Cd-induced neuronal apoptosis in mouse brain partially by inhibiting ROS-dependent activation of Akt/mTOR pathway. The findings highlight that NAC may be exploited for prevention and treatment of Cd-induced neurodegenerative diseases. PMID:24299490

  3. The accumulation of un-repairable DNA damage in laminopathy progeria fibroblasts is caused by ROS generation and is prevented by treatment with N-acetyl cysteine.

    PubMed

    Richards, Shane A; Muter, Joanne; Ritchie, Pamela; Lattanzi, Giovanna; Hutchison, Christopher J

    2011-10-15

    Fibroblasts from patients with the severe laminopathy diseases, restrictive dermopathy (RD) and Hutchinson Gilford progeria syndrome (HGPS), are characterized by poor growth in culture, the presence of abnormally shaped nuclei and the accumulation of DNA double-strand breaks (DSB). Here we show that the accumulation of DSB and poor growth of the fibroblasts but not the presence of abnormally shaped nuclei are caused by elevated levels of reactive oxygen species (ROS) and greater sensitivity to oxidative stress. Basal levels of ROS and sensitivity to H(2)O(2) were compared in fibroblasts from normal, RD and HGPS individuals using fluorescence activated cell sorting-based assays. Basal levels of ROS and stimulated levels of ROS were both 5-fold higher in the progeria fibroblasts. Elevated levels of ROS were correlated with lower proliferation indices but not with the presence of abnormally shaped nuclei. DSB induced by etoposide were repaired efficiently in normal, RD and HGPS fibroblasts. In contrast, DSB induced by ROS were repaired efficiently in normal fibroblasts, but in RD and HGPS fibroblasts many ROS-induced DSB were un-repairable. The accumulation of ROS-induced DSB appeared to cause the poor growth of RD and HGPS fibroblasts, since culture in the presence of the ROS scavenger N-acetyl cysteine (NAC) reduced the basal levels of DSB, eliminated un-repairable ROS-induced DSB and greatly improved population-doubling times. Our findings suggest that un-repaired ROS-induced DSB contribute significantly to the RD and HGPS phenotypes and that inclusion of NAC in a combinatorial therapy might prove beneficial to HGPS patients.

  4. pH-dependent optical properties of N-acetyl-L-cysteine-capped ZnSe(S) nanocrystals with intense/stable emissions

    NASA Astrophysics Data System (ADS)

    Soheyli, Ehsan; Sahraei, Reza; Nabiyouni, Gholamreza

    2017-03-01

    In the present study, a series of aqueous-based ZnSe(S) nanocrystals (NCs) was prepared at different solution pH ranging from 8 to 11.9, and using N-acetyl-L-cysteine (NAC) as capping agent. In addition to zinc blende structure, the X-ray diffraction studies demonstrated the quantum size regime of the ZnSe(S) NCs. To gain further insight toward the influence of the quantum confinement and pH values on optical properties of the as-prepared NCs, their UV-visible absorption and photoluminescence spectra were systematically analyzed. The absorption spectra experienced a red shift from 340 to 382 nm as the pH increased from 8.0 to 11.9, indicating the growth of the as-prepared ZnSe(S) NCs. The emission spectra also show the obvious red shift and the relative area of excitonic to trap emission, firstly increases from pH = 8.0 to 10.7, and then decreases by further increasing of the solution pH. The initial behavior might be due to the improved surface passivation of the trap dangling states by better deprotonation of thiol groups in NAC, whereas at pH >10.7, the faster growth rate of the ZnSe(s) NCs may lead to the formation of many defect sites. All of these phenomena were combined in the scheme which displays the effect of quantum confinement and solution pH on variation of the excitonic and trap-related emissions.

  5. N-acetyl-S-(n-propyl)-l-cysteine in urine from workers exposed to 1-bromopropane in foam cushion spray adhesives.

    PubMed

    Hanley, Kevin W; Petersen, Martin R; Cheever, Kenneth L; Luo, Lian

    2009-10-01

    1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br((-))] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br((-)) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers.

  6. N-Acetyl-D-Glucosamine Kinase Interacts with Dynein-Lis1-NudE1 Complex and Regulates Cell Division

    PubMed Central

    Sharif, Syeda Ridita; Islam, Ariful; Moon, Il Soo

    2016-01-01

    N-acetyl-D-glucosamine kinase (GlcNAc kinase or NAGK) primarily catalyzes phosphoryl transfer to GlcNAc during amino sugar metabolism. Recently, it was shown NAGK interacts with dynein light chain roadblock type 1 (DYNLRB1) and upregulates axo-dendritic growth, which is an enzyme activity-independent, non-canonical structural role. The authors examined the distributions of NAGK and NAGK-dynein complexes during the cell cycle in HEK293T cells. NAGK was expressed throughout different stages of cell division and immunocytochemistry (ICC) showed NAGK was localized at nuclear envelope, spindle microtubules (MTs), and kinetochores (KTs). A proximity ligation assay (PLA) for NAGK and DYNLRB1 revealed NAGK-dynein complex on nuclear envelopes in prophase cells and on chromosomes in metaphase cells. NAGK-DYNLRB1 PLA followed by Lis1/NudE1 immunostaining showed NAGK-dynein complexes were colocalized with Lis1 and NudE1 signals, and PLA for NAGK-Lis1 showed similar signal patterns, suggesting a functional link between NAGK and dynein-Lis1 complex. Subsequently, NAGK-dynein complexes were found in KTs and on nuclear membranes where KTs were marked with CENP-B ICC and nuclear membrane with lamin ICC. Furthermore, knockdown of NAGK by small hairpin (sh) RNA was found to delay cell division. These results indicate that the NAGK-dynein interaction with the involvements of Lis1 and NudE1 plays an important role in prophase nuclear envelope breakdown (NEB) and metaphase MT-KT attachment during eukaryotic cell division. PMID:27646688

  7. Enhanced anticancer effect and reduced toxicity of doxorubicin in combination with thymoquinone released from poly-N-acetyl glucosamine nanomatrix in mice bearing solid Ehrlish carcinoma.

    PubMed

    El-Ashmawy, Nahla E; Khedr, Eman G; Ebeid, El-Zeiny M; Salem, Mohamed L; Zidan, Abdel-Aziz A; Mosalam, Esraa M

    2017-09-07

    The incidence of breast cancer remarkably increases all over the world. Therefore, there is a great demand to introduce new approaches into cancer treatment field. The current study was designated to evaluate the role of doxorubicin (DOX) and/or thymoquinone (TQ) nanomatrix in potentiating the cytotoxicity of either drug, and to investigate the ability of TQ to reduce cardiotoxicity of DOX in solid Ehrlich carcinoma (SEC)-bearing mice. DOX and TQ were loaded into F2 gel, which is a fully-acetylated poly-N-acetyl glucosamine nanofiber. SEC was induced in female albino mice as a model for experimentally induced breast cancer. Mice were randomly divided into eight groups (n=10): normal control, tumor control, F2 gel, free DOX, DOX+F2 gel, free TQ, TQ+F2 gel, and DOX+TQ+F2 gel. On day 28th from tumor inoculation, mice were sacrificed and blood samples were collected for measurement of the cardiac markers; lactate dehydrogenase (LDH) and creatine kinase (CK-MB). In addition, cardiac tissue was utilized for determination of lipid peroxide, and tumor tissue was used for measurement of anti-apoptotic protein Bcl-2 as well as gene expression of the tumor suppressor gene P53. DOX and/or TQ showed a significant reduction in tumor volume, cardiac markers, tumor Bcl-2, and P53 upregulation compared to free conventional therapies. Co-treatment with DOX+TQ+F2 gel was superior to all other groups in exerting beneficial effects. Use of TQ as an adjuvant therapy with DOX could improve its cytotoxic effects and limit its cardiac toxicity. Furthermore, loading of DOX and/or TQ into F2 gel showed a remarkable anti-cancer activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Neuroprotective role of an N-acetyl serotonin derivative via activation of tropomyosin-related kinase receptor B after subarachnoid hemorrhage in a rat model.

    PubMed

    Tang, Junjia; Hu, Qin; Chen, Yujie; Liu, Fei; Zheng, Yun; Tang, Jiping; Zhang, Jianmin; Zhang, John H

    2015-06-01

    N-[2-(5-hydroxy-1H-indol-3-yl) ethyl]-2-oxopiperidine-3-carboxamide (HIOC), an N-acetyl serotonin derivative, selectively activates tropomyosin-related kinase receptor B (TrkB). This study is to investigate a potential role of HIOC on ameliorating early brain injury after experimental subarachnoid hemorrhage (SAH). One hundred and fifty-six adult male Sprague-Dawley rats were used. SAH model was induced by endovascular perforation. TrkB small interfering RNA (siRNA) or scramble siRNA was injected intracerebroventricularly 24h before SAH. HIOC was administrated intracerebroventricularly 3h after SAH and compared with brain-derived neurotrophic factor (BDNF). SAH grade and neurologic scores were evaluated for the outcome study. For the mechanism study, the expression of TrkB, phosphorylated TrkB (p-TrkB), phosphorylated extracellular signal regulated kinase (p-ERK), B-cell lymphoma 2 (Bcl-2) and cleaved caspase 3 (CC3) was detected by Western blots, and neuronal injury was determined by double immunofluorescence staining of neuronal nuclei and terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end-labeling. Knocking down of TrkB decreased the expression of Bcl-2 and aggravated neurologic deficits 24h after SAH. HIOC activated TrkB/ERK pathway, decreased neuronal cell death, and improved neurobehavioral outcome, and these effects were abolished by TrkB siRNA. HIOC was more potent than BDNF in reduction of apoptosis 24h post-SAH. Thus, we conclude that administration of HIOC activated TrkB/ERK signaling cascade and attenuated early brain injury after SAH. HIOC may be a promising agent for further treatment for SAH and other stroke events.

  9. Postprandial glycemic control conditions in relation to urinary N-acetyl-β-D-glucosaminidase in patients with type 2 diabetes mellitus without low glomerular filtration rate.

    PubMed

    Ouchi, Motoshi; Oba, Kenzo; Motoyama, Masayuki; Tsunoda, Misako; Yamashita, Hidetoshi; Aoyama, Junya; Saigusa, Taro; Ishii, Kazuhito; Yano, Hiroyuki; Hashimoto, Masao; Sekimizu, Ken-Ichi; Suzuki, Tatsuya; Nakano, Hiroshi

    2014-01-01

    This study assessed the relationship between the serum level of 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycemia, and the ratio of the urinary activity of N-acetyl-β-D-glucosaminidase (NAG) to creatinine (NAG index) in patients with type 2 diabetes mellitus. This was a cross-sectional study with 153 patients who had an estimated glomerular filtration rate of ≥60 mL/min/1.73 m(2) and no proteinuria and who had never been treated with oral hypoglycemic agents or insulin. On the basis of 1,5-AG levels, the patients were divided into a High 1,5-AG group (>14.0 μg/mL) and a Low 1,5-AG group (≤14.0 μg/mL). The logarithmically transformed NAG index was significantly higher in the Low 1,5-AG group than in the High 1,5-AG group when all glycated hemoglobin (HbA1c) levels were included. The logarithmically transformed NAG index was lowest in the High 1,5-AG group with an HbA1c level of ≤6.4% and was highest in the Low 1,5-AG group with an HbA1c level of ≥7.5%. Multivariate regression analysis showed that the NAG index had a higher independent association with 1,5-AG than with HbA1c or the fasting plasma glucose level. In all models, multivariate regression analyses showed that the NAG index was correlated with age. These results suggest that postprandial hyperglycemia correlates with early renal tubule injury in type 2 diabetes mellitus.

  10. N-Acetyl cysteine protects diabetic mouse derived mesenchymal stem cells from hydrogen-peroxide-induced injury: A novel hypothesis for autologous stem cell transplantation.

    PubMed

    Ali, Fatima; Khan, Mohsin; Khan, Shaheen N; Riazuddin, Sheikh

    2016-03-01

    Stem cell transplantation is one of the therapeutic options available to repair damaged organs. However, transplanted cells entail several challenges including their survival in diabetes-affected injured tissue. This study was designed to determine the effects of preconditioning of mesenchymal stem cells (MSCs) with N-acetyl cysteine (NAC), a widely used antioxidant drug. Diabetic-mouse-derived MSCs (blood glucose ≥ 300 mg/dL) were preconditioned with 30 mM NAC for 1 hour followed by oxidative injury with 100 μM hydrogen peroxide (H2O2) for 1 hour. Gene expression analysis showed marked upregulation of prosurvival genes (Akt and Bcl-2) and significantly downregulated expression of proapoptotic and stress genes (Capase-3, Bax, Bak, p53, p38, and NF-κB) in the 30 mM-NAC-treated group when compared with those cells treated with H2O2 alone. NAC preconditioning improved cell viability, decreased lactate dehydrogenase release, β-galactosidase activity, and Annexin-V-positive cells. Also, amelioration of oxidative stress, as shown by a decrease in malondialdehyde level and an increase in superoxide dismutase and catalase activities and glutathione level, was observed in the 30 mM-NAC-treated group in comparison to cells treated with H2O2 alone. This study demonstrates the potential benefits of pharmacological preconditioning of diabetic-mouse-derived MSCs with NAC for amelioration of apoptosis and oxidative stress in H2O2 induced injury. Copyright © 2016. Published by Elsevier Taiwan LLC.

  11. N-Acetyl-S-(n-Propyl)-L-Cysteine in Urine from Workers Exposed to 1-Bromopropane in Foam Cushion Spray Adhesives

    PubMed Central

    Hanley, Kevin W.; Petersen, Martin R.; Cheever, Kenneth L.; Luo, Lian

    2009-01-01

    1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br(−)] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br(−) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers. PMID:19706636

  12. Combinations of N-Acetyl-S-(N-2-Phenethylthiocarbamoyl)-L-Cysteine and myo-inositol inhibit tobacco carcinogen-induced lung adenocarcinoma in mice.

    PubMed

    Kassie, Fekadu; Matise, Ilze; Negia, Mesfin; Lahti, David; Pan, Yunqian; Scherber, Robyn; Upadhyaya, Pramod; Hecht, Stephen S

    2008-09-01

    We have previously generated convincing evidence that combinations of N-acetyl-S-(N-2-phenethylthiocarbamoyl)-L-cysteine (PEITC-NAC; 3 micromol/g diet) and myo-inositol (MI; 56 micromol/g diet) were significantly more effective than the individual compounds as inhibitors of tobacco smoke carcinogen-induced lung tumorigenesis in A/J mice. In this study, we further investigated the efficacy of combinations of PEITC-NAC (9 or 15 micromol/g diet) and MI (56 micromol/g diet). Female A/J mice were treated with a mixture of the tobacco smoke carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and benzo[a]pyrene by gavage once weekly for 8 weeks. PEITC-NAC plus MI was given in the diet beginning at 1 day after the 4th of eight carcinogen treatments (temporal sequence A) or 1 week after the last carcinogen treatment (temporal sequence B). Regardless of the dose of carcinogen or PEITC-NAC plus MI, or temporal sequence, administration of PEITC-NAC plus MI significantly reduced the multiplicity of gross tumors and, in most instances, adenocarcinoma. PEITC-NAC plus MI was particularly effective against bigger tumors. The observed inhibition of lung tumorigenesis by PEITC-NAC plus MI was attributed, at least partly, to inhibition of cell proliferation and induction of apoptosis. These results clearly show the efficacy of PEITC-NAC plus MI in the prevention of tobacco carcinogen-induced lung adenocarcinoma in A/J mice and provide a basis for future evaluation of PEITC-NAC plus MI in clinical trials as a chemopreventive agent for current and former smokers.

  13. Effect of alpha-ketoglutarate and N-acetyl cysteine on cyanide-induced oxidative stress mediated cell death in PC12 cells.

    PubMed

    Satpute, R M; Hariharakrishnan, J; Bhattacharya, R

    2010-06-01

    Cyanide is a mitochondrial poison, which is ubiquitously present in the environment. Cyanide-induced oxidative stress is known to play a key role in mediating the neurotoxicity and cell death in rat pheochromocytoma (PC12) cells. PC12 cells are widely used as a model for neurotoxicity assays in vitro. In the present study, we investigated the protective effects of alpha-ketoglutarate (A-KG), a potential cyanide antidote, and N-acetyl cysteine (NAC), an antioxidant against toxicity of cyanide in PC12 cells. Cells were treated with various concentrations (0.625-1.25 mM) of potassium cyanide (KCN) for 4 hours, in the presence or absence of simultaneous treatment of A-KG (0.5 mM) and NAC (0.25 mM). Cyanide caused marked decrease in the levels of cellular antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Lipid peroxidation indicated by elevated levels of malondialdehyde (MDA) was found to be accompanied by decreased levels of reduced glutathione (GSH) and total antioxidant status (TAS) of the cells. Cyanide-treated cells showed notable increase in caspase-3 activity and induction of apoptotic type of cell death after 24 hours. A-KG and NAC alone were very effective in restoring the levels of GSH and TAS, but together they significantly resolved the effects of cyanide on antioxidant enzymes, MDA levels, and caspase-3 activity. The present study reveals that combination of A-KG and NAC has critical role in abbrogating the oxidative stress-mediated toxicity of cyanide in PC12 cells. The results suggest potential role of A-KG and NAC in cyanide antagonism.

  14. [Pharmacological effects of N-acetyl-L-cysteine on the respiratory tract. (I). Quantitative and qualitative changes in respiratory tract fluid and sputum (author's transl)].

    PubMed

    Kogi, K; Saito, T; Kasé, Y; Hitoshi, T

    1981-06-01

    The following three experiments were performed to determine the effects of N-acetyl-L-cysteine (NAC) on the quantity and quality of respiratory tract fluid (RTF) and sputum. All drugs used were administered into the stomach through a gastric tube. 1) Indirect measurement of bronchial secretion in rats, which was expressed by the amounts of dye excreted into the respiratory tract, was carried out according the the Sakuno's method, with some modification. Some expectorants of the secretomotor type, such as bromhexine and pilocarpine, significantly increased the secretion, even at low doses. On the other hand, mucolytic agents such as NAC augmented the secretion only in doses of 500 to 1500 mg/kg. 2)As a direct method of measurements, Kasé's modification of Perry and Boyd's method was used to collect RTF, quantitatively, from rabbits. The RTF of healthy rabbits was colorless and watery. The administration of NAC in doses of 500 to 1500 mg/kg augmented the output volume and RTF became slightly turbid, probably due to an increase in the viscous mucus. 3) Rabbits with subacute bronchitis were prepared by long-term exposure to air contaminated with SO2 gas and sputa were collected before and after administration of NAC, respectively, according to the Kase's method. The sputa were opalescent and viscous gel included nodular masses. The administration of NAC, 1000 and 1500 mg/kg resulted in a dose dependent decrease in the relative viscosity. The percent-decreased in viscosity with NAC was statistically correlated with that in amounts of dry matter, those in protein and polysaccharide in the sputa. From the results described above, it was concluded that NAC given into the stomach can liquefy sputum by splitting mucoprotein disulphide linkages, that is, altering the rheological characteristics of sputum to facilitate expectoration.

  15. Sensitive Electrochemiluminescence Immunosensor for Detection of N-Acetyl-β-d-glucosaminidase Based on a "Light-Switch" Molecule Combined with DNA Dendrimer.

    PubMed

    Wang, Haijun; Yuan, Yali; Zhuo, Ying; Chai, Yaqin; Yuan, Ruo

    2016-06-07

    Here, a novel "light-switch" molecule of Ru (II) complex ([Ru(dcbpy)2dppz](2+)-DPEA) with self-enhanced electrochemiluminescence (ECL) property is proposed, which is almost nonemissive in aqueous solution but is brightly luminescent when it intercalates into DNA duplex. Owing to less energy loss and shorter electron-transfer distance, the intramolecular ECL reaction between the luminescent [Ru(dcbpy)2dppz](2+) and coreactive tertiary amine group in N,N-diisopropylethylenediamine (DPEA) makes the obtained "light-switch" molecule possess much higher light-switch efficiency compared with the traditional "light-switch" molecule. For increasing the loading amount and further enhancing the luminous efficiency of the "light-switch" molecule, biotin labeled DNA dendrimer (the fourth generation, G4) is prepared from Y-shape DNA by a step-by-step assembly strategy, which provides abundant intercalated sites for [Ru(dcbpy)2dppz](2+)-DPEA. Meanwhile, the obtained nanocomposite (G4-[Ru(dcbpy)2dppz](2+)-DPEA) could well bind with streptavidin labeled detection antibody (SA-Ab2) due to the existence of abundant biotin. Through sandwiched immunoreaction, an ECL immunosensor was fabricated for sensitive determination of N-acetyl-β-d-glucosaminidase (NAG), a typical biomarker for diabetic nephropathy (DN). The detemination linear range was 0.1 pg mL(-1) to 1 ng mL(-1), and the detection limit was 0.028 pg mL(-1). The developed strategy combining the ECL self-enhanced "light-switch" molecular and DNA nanotechnology offers an effective signal amplification mean and provides ample potential for further bioanalysis and clinical study.

  16. N-Acetyl cysteine does not prevent liver toxicity from chronic low-dose plus subacute high-dose paracetamol exposure in young or old mice.

    PubMed

    Kane, Alice Elizabeth; Huizer-Pajkos, Aniko; Mach, John; McKenzie, Catriona; Mitchell, Sarah Jayne; de Cabo, Rafael; Jones, Brett; Cogger, Victoria; Le Couteur, David G; Hilmer, Sarah Nicole

    2016-06-01

    Paracetamol is an analgesic commonly used by people of all ages, which is well documented to cause severe hepatotoxicity with acute overexposures. The risk of hepatotoxicity from nonacute paracetamol exposures is less extensively studied, and this is the exposure most common in older adults. Evidence on the effectiveness of N-acetyl cysteine (NAC) for nonacute paracetamol exposures, in any age group, is lacking. This study aimed to examine the effect of long-term exposure to therapeutic doses of paracetamol and subacute paracetamol overexposure, in young and old mice, and to investigate whether NAC was effective at preventing paracetamol hepatotoxicity induced by these exposures. Young and old male C57BL/6 mice were fed a paracetamol-containing (1.33 g/kg food) or control diet for 6 weeks. Mice were then dosed orally eight times over 3 days with additional paracetamol (250 mg/kg) or saline, followed by either one or two doses of oral NAC (1200 mg/kg) or saline. Chronic low-dose paracetamol exposure did not cause hepatotoxicity in young or old mice, measured by serum alanine aminotransferase (ALT) elevation, and confirmed by histology and a DNA fragmentation assay. Subacute paracetamol exposure caused significant hepatotoxicity in young and old mice, measured by biochemistry (ALT) and histology. Neither a single nor double dose of NAC protected against this toxicity from subacute paracetamol in young or old mice. This finding has important clinical implications for treating toxicity due to different paracetamol exposure types in patients of all ages, and implies a need to develop new treatments for subacute paracetamol toxicity. © 2016 Société Française de Pharmacologie et de Thérapeutique.

  17. N-acetyl-seryl-aspartyl-lysyl-proline attenuates renal injury and dysfunction in hypertensive rats with reduced renal mass: council for high blood pressure research.

    PubMed

    Liao, Tang-Dong; Yang, Xiao-Ping; D'Ambrosio, Martin; Zhang, Yanlu; Rhaleb, Nour-Eddine; Carretero, Oscar A

    2010-02-01

    N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a naturally occurring peptide of which the plasma concentration is increased 4- to 5-fold by angiotensin-converting enzyme inhibitors. We reported previously that, in models of both hypertension and postmyocardial infarction, Ac-SDKP reduces cardiac inflammation and fibrosis. However, it is unknown whether Ac-SDKP can prevent or reverse renal injury and dysfunction in hypertension. In the present study, we tested the hypothesis that, in rats with 5/6 nephrectomy (5/6Nx)-induced hypertension, Ac-SDKP reduces renal damage, albuminuria, and dysfunction by decreasing inflammatory cell infiltration and renal fibrosis and by increasing nephrin protein. Ac-SDKP (800 microg/kg per day, SC via osmotic minipump) or vehicle was either started 7 days before 5/6Nx (prevention) and continued for 3 weeks or started 3 weeks after 5/6Nx (reversal) and continued for another 3 weeks. Rats with 5/6Nx developed high blood pressure, left ventricular hypertrophy, albuminuria, decreased glomerular filtration rate, and increased macrophage infiltration (inflammation) and renal collagen content (fibrosis). Ac-SDKP did not affect blood pressure or left ventricular hypertrophy in either group; however, it significantly reduced albuminuria, renal inflammation, and fibrosis and improved glomerular filtration rate in both prevention and reversal groups. Moreover, slit diaphragm nephrin protein expression in the glomerular filtration barrier was significantly decreased in hypertensive rats. This effect was partially prevented or reversed by Ac-SDKP. We concluded that Ac-SDKP greatly attenuates albuminuria and renal fibrosis and improves renal function in rats with 5/6Nx. These effects may be related to decreased inflammation (macrophages) and increased nephrin protein.

  18. Arsenic Metabolites, Including N-Acetyl-4-hydroxy-m-arsanilic Acid, in Chicken Litter from a Roxarsone-Feeding Study Involving 1600 Chickens.

    PubMed

    Yang, Zonglin; Peng, Hanyong; Lu, Xiufen; Liu, Qingqing; Huang, Rongfu; Hu, Bin; Kachanoski, Gary; Zuidhof, Martin J; Le, X Chris

    2016-07-05

    The poultry industry has used organoarsenicals, such as 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, ROX), to prevent disease and to promote growth. Although previous studies have analyzed arsenic species in chicken litter after composting or after application to agricultural lands, it is not clear what arsenic species were excreted by chickens before biotransformation of arsenic species during composting. We describe here the identification and quantitation of arsenic species in chicken litter repeatedly collected on days 14, 24, 28, 30, and 35 of a Roxarsone-feeding study involving 1600 chickens of two strains. High performance liquid chromatography separation with simultaneous detection by both inductively coupled plasma mass spectrometry and electrospray ionization tandem mass spectrometry provided complementary information necessary for the identification and quantitation of arsenic species. A new metabolite, N-acetyl-4-hydroxy-m-arsanilic acid (N-AHAA), was identified, and it accounted for 3-12% of total arsenic. Speciation analyses of litter samples collected from ROX-fed chickens on days 14, 24, 28, 30, and 35 showed the presence of N-AHAA, 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA), inorganic arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA(V)), dimethylarsinic acid (DMA(V)), and ROX. 3-AHPAA accounted for 3-19% of the total arsenic. Inorganic arsenicals (the sum of As(III) and As(V)) comprised 2-6% (mean 3.5%) of total arsenic. Our results on the detection of inorganic arsenicals, methylarsenicals, 3-AHPAA, and N-AHAA in the chicken litter support recent findings that ROX is actually metabolized by the chicken or its gut microbiome. The presence of the toxic metabolites in chicken litter is environmentally relevant as chicken litter is commonly used as fertilizer.

  19. Effect of Antifibrotic MicroRNAs Crosstalk on the Action of N-acetyl-seryl-aspartyl-lysyl-proline in Diabetes-related Kidney Fibrosis

    PubMed Central

    Srivastava, Swayam Prakash; Shi, Sen; Kanasaki, Megumi; Nagai, Takako; Kitada, Munehiro; He, Jianhua; Nakamura, Yuka; Ishigaki, Yasuhito; Kanasaki, Keizo; Koya, Daisuke

    2016-01-01

    N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is an endogenous antifibrotic peptide. We found that suppression of AcSDKP and induction of dipeptidyl peptidase-4 (DPP-4), which is associated with insufficient levels of antifibrotic microRNA (miR)s in kidneys, were imperative to understand the mechanisms of fibrosis in the diabetic kidneys. Analyzing streptozotocin (STZ)-induced diabetic mouse strains, diabetic CD-1 mice with fibrotic kidneys could be differentiated from less-fibrotic diabetic 129Sv mice by suppressing AcSDKP and antifibrotic miRs (miR-29s and miR-let-7s), as well as by the prominent induction of DPP-4 protein expression/activity and endothelial to mesenchymal transition. In diabetic CD-1 mice, these alterations were all reversed by AcSDKP treatment. Transfection studies in culture endothelial cells demonstrated crosstalk regulation of miR-29s and miR-let-7s against mesenchymal activation program; such bidirectional regulation could play an essential role in maintaining the antifibrotic program of AcSDKP. Finally, we observed that AcSDKP suppression in fibrotic mice was associated with induction of both interferon-γ and transforming growth factor-β signaling, crucial molecular pathways that disrupt antifibrotic miRs crosstalk. The present study provides insight into the physiologically relevant antifibrotic actions of AcSDKP via antifibrotic miRs; restoring such antifibrotic programs could demonstrate potential utility in combating kidney fibrosis in diabetes. PMID:27425816

  20. RNA therapeutics directed to the non coding regions of APP mRNA, in vivo anti-amyloid efficacy of paroxetine, erythromycin, and N-acetyl cysteine.

    PubMed

    Tucker, Stephanie; Ahl, Michelle; Cho, Hyun-Hee; Bandyopadhyay, Sanghamitra; Cuny, Gregory D; Bush, Ashley I; Goldstein, Lee E; Westaway, David; Huang, Xudong; Rogers, Jack T

    2006-07-01

    Lead compounds directed to the 5' leader of the Amyloid Precursor Protein transcript (i.e., paroxetine (SSRI), N-acetyl cysteine (antioxidant), and erythromycin (macrolide antibiotic)) were employed in a pilot study to evaluate their anti-amyloid efficacy in the TgCRND8 transgenic mouse model for Alzheimer's Disease (AD). The relative levels of Abeta peptide were reduced after exposure of mice to paroxetine (N=5), NAC (N=7), and erythromycin (N=7) relative to matched placebo counterparts. Paroxetine limited the levels of APP holoprotein and total Abeta peptide levels (measurements of Abeta were performed at two separate sites by quantitative western blotting and ELISA assay). The paroxetine data provided proof-of-concept for our strategy for further screening the APP 5'UTR target to identify novel drugs that exhibit anti-amyloid efficacy in vivo. Erythromycin and azithromycin were macrolide antibiotics that markedly changed the cleavage of the APP C-Terminal Fragment (CTF) in SH-SY5Y cells. Erythromycin provided orally to TgCRND8 mice consistently (100%) reduced brain Abeta(1-42) levels. These data demonstrated a highly statistically significant anti-amyloid trend for paroxetine, NAC and erythromycin. The potential for conducting further studies with these compounds using larger cohorts of TgCRND8 mice is discussed, particularly since erythromycin has recently been exposed to mice for a further 6 months (N=6). It will be possible to employ the chemical structures of paroxetine and erythromycin as starting points for drug design and development for AD therapeutics.

  1. Metallothionein 1A polymorphisms may influence urine uric acid and N-acetyl-beta-D-glucosaminidase (NAG) excretion in chronic lead-exposed workers.

    PubMed

    Yang, Chen-Cheng; Chen, Hsin-I; Chiu, Yu-Wen; Tsai, Chih-Hung; Chuang, Hung-Yi

    2013-04-05

    Lead is a renal toxin, and susceptibility to lead varies between individuals. Metallothionein (MT) is known for its metal scavenging role. The aim of the study was to investigate the association of blood lead levels, urinary uric acid (UA) and N-acetyl-beta-d-glucosaminidase (NAG) in chronic occupational lead-exposed workers, and to study whether the association was influenced by MT1A gene polymorphisms. In this cross-sectional study, 412 lead-exposed workers participated. Their annual health examination data and renal function markers were collected after the Institutional Review Broad of Kaohsiung Medical University Hospital approved the study and consent letters were obtained. From the blood samples, DNA was extracted and used for real-time PCR typing of 2 MT1A single nucleotide polymorphisms (SNPs): rs11640851 and rs8052394 on exons 2 and 3. Descriptive analysis, one-way ANOVA, and multiple linear regressions were performed. There was a signifi