Besides medical application, 4-hydroxybutyrate (4-HB) is a precursor of P3HB4HB, a bioplastic showing excellent physical properties and degradability. Escherichia coli S17-1 (pZL-dhaT-aldD) can transform 1, 4-butanediol (1,4-BD) into 4HB with participation of cofactor NAD. To enhance productivity, nicotinic acid phosphoribosyltransferase (PncB) and nicotinamide adenine dinucleotide synthetase (NadE) were overexpressed to increase intracellular nicotinamide adenine dinucleotide concentration and promote reaction process. The shake flask fermentation result showed that the conversion rate increased by 13.03% with help of PncB-NadE, leading to 4.87 g/L 4HB from 10 g/L 1,4-BD, and productivity was increased by 40.91% to 1.86 g/g. These results demonstrated that expression of PncB and NadE is beneficial for conversion of 1,4-BD to 4HB.
Amide Synthases ; metabolism ; Butylene Glycols ; chemistry ; metabolism ; Escherichia coli ; metabolism ; Fermentation ; Hydroxybutyrates ; chemistry ; metabolism ; Pentosyltransferases ; metabolism

This study was purposed to explore the relationship between asparagine synthetase (AsnS) mRNA expression level and the sensitivity of leukemic cell lines to L-asparaginase. The AsnS mRNA expression level in 8 cell lines (Jurkat, HL-60, U937, NB4, THP-1, Namalwa, Karpas299 and K562) was determined by real-time quantitative PCR (RQ-PCR) based on fluorescence dye Eva Green before and after treatment with L-Asp, and the cell proliferation rates were analyzed by CCK-8 assay. The results showed that there was a significant disparity of AsnS expression level in 8 cell lines, and there were significant increases of AsnS expression level in cells co-cultured with L-Asp (p < 0.05). Of all these eight cell lines, cells sensitive to L-asparaginase had lower AsnS expression level and cells resistant to L-asparaginase had higher AsnS expression. U937 which was the most sensitive to L-asparaginase had the lowest AsnS expression level, while K562 was natural resistant to L-asparaginase and possessed of the highest AsnS level. It is concluded that the AsnS plays a critical role in regulating cellular biological behavior after depletion of asparagine, the AsnS mRNA expression level in cells reflects the sensitivity of cells to L-Asp. The results may imply the possibility for the use of L-asparaginase in leukemia with lower AsnS expression level.
Asparaginase ; metabolism ; pharmacology ; Aspartate-Ammonia Ligase ; metabolism ; Cell Line, Tumor ; Humans ; Leukemia ; enzymology

OBJECTIVETo detect the expression level of asparagine synthetase (ASNS) in patients with relapsed or refractory extranodal NK/T cell lymphoma and explore its clinical significance.

METHODSTen patients with relapsed or refractory extranodal NK/T cell lymphoma admitted in our department from January, 2013 to January, 2016 were analyzed. The diagnoses were confirmed by pathological and immunohistochemical examination following failed chemotherapies in all cases. Branched DNA-liquidchip technique (bDNA-LCT) was used for detecting ASNS mRNA expression in paraffin-embedded tissue sections in the 10 cases of relapsed or refractory extranodal NK/T cell lymphoma and in 5 cases of chronic rhinitis. The correlations were analyzed between ASNS expression and the clinicopathological features and outcomes of the patients with failed chemotherapy regimens containing asparaginasum.

RESULTSSix out of the 10 patients with relapsed or refractory extranodal NK/T cell lymphoma died due to diseaseprogression. The expression level of ASNS was significantly higher in the lymphoma tissues than in tissue specimens of chronic rhinitis (P<0.05). The expression level of ASNS was associated with the International Prognostic Index (P=0.023) in patients with relapsed or refractory extranodal NK/T cell lymphoma, and Kaplan-Meier curve showed that a high ASNS expression was correlated with a reduced overall survival and progression-free survival of the patients.

CONCLUSIONAsparaginasum-based chemotherapy regimens are recommended for treatment of relapsed or refractory extranodal NK/T cell lymphoma with low ASNS expressions.

Aspartate-Ammonia Ligase ; metabolism ; Disease-Free Survival ; Humans ; Lymphoma, Extranodal NK-T-Cell ; enzymology ; Recurrence

OBJECTIVETo determine whether the high level of asparagine synthetase (AS) expression in childhood acute lymphocytic leukemia (ALL) is associated with an inferior prognosis.

METHODSAS mRNA level in leukemic cells from 53 newly diagnosed ALL children was measured by real time fluorescent quantitative PCR method. Patients were divided into groups according to their relapse risk and outcome, and the AS expression levels in each group were compared. The survival rates in different AS expressing level groups were estimated and compared.

RESULTSThe highest level of AS [median 17.25 (2.48-46. 82)] was observed in children failed remission, intermediate level [14.28 (3.20-54.47)] in relapsed children and the lowest level [5.08 (0.84-54.92)] in children with continuous complete remission (CCR) (P<0.05). The AS mRNA level [14.93 (2.48-54.47)] in children with poor outcome (un-remission and relapsed) was significantly higher than that in children in CCR (P<0.01). The two-year estimated disease free survival was much lower in children with high AS expression (53.8%) than in those with low AS expression (84.6%) (P<0.05).

CONCLUSIONHigh expression of AS is associated with a poor outcome in ALL children.

Adolescent ; Aspartate-Ammonia Ligase ; metabolism ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; enzymology ; Prognosis

High expression of cellular asparagine synthetase (AS) is a causative factor for the resistance of leukemic cell to L-asparaginase therapy. This study was aimed to find single nucleotide polymorphism (SNPs) in the promotor region of asparagine synthetase (AS) gene and to determine if these SNPs have influence on the transcriptional activity of AS promotor. The DNA sequences of AS promoter (pAS) from 82 leukemic children and 45 controls were determined to screen for SNPs in this region and the AS mRNA level in these samples was quantified using real-time PCR assay. The results indicated that three SNPs were found in the sequenced pAS fragment. They were -239C/T, -92G/A and -62A/T respectively. The frequency of -92A allele was higher in leukemic samples than that in nonleukemic control (P<0.05). The gene expression level differed among the individuals with genotype of the -92G/A SNP, and the descending order was as follows: GA heterozygote > AA homozygote > GG homozygote. It is concluded that some features in leukemia might associate with SNP on -92A locus, and this SNP in pAS can be one of the factors influencing transcriptional activity of AS gene. The existence of the -92A allele variant contributes to a high expression of AS gene.
Aspartate-Ammonia Ligase ; genetics ; Child ; Female ; Humans ; Leukemia, Myeloid, Acute ; enzymology ; genetics ; Male ; Polymorphism, Single Nucleotide ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; enzymology ; genetics ; Promoter Regions, Genetic ; genetics

OBJECTIVETo study the cellular activity of asparagine synthetase in different types of childhood acute lymphoblastic leukemia (ALL).

METHODSThe cellular activity of asparagine synthetase was detected by HPLC-FLD and Protein measurement in 28 ALL children (7 cases of T-ALL and 21 cases of B-lymphoid lineage ALL) before chemotherapy.

RESULTSThe asparagines synthetase activity levels in T-ALL children were significantly higher than those of the B-lymphoid lineage ALL patients, with the median activity level of 9.3 nM Asn/mg protein/hr vs 5.2 nM Asn/mg protein/hr (P < 0.05). The distribution of the asparagine synthetase activity demonstrated a polymorphism in either T-ALL or B-lymphoid lineage ALL patients.

CONCLUSIONSThe cellular activity of asparagines synthetase in ALL patients is presented with a polymorphism distribution. The asparagines synthetase activity levels in T-ALL are significantly higher than in B-lymphoid lineage ALL.

Asparaginase ; therapeutic use ; Aspartate-Ammonia Ligase ; genetics ; metabolism ; Child ; Core Binding Factor Alpha 2 Subunit ; genetics ; Female ; Humans ; Male ; Oncogene Proteins, Fusion ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; enzymology ; RNA, Messenger ; analysis

No abstract available.
Animals ; Electroshock* ; Glutamate Decarboxylase* ; Glutamate-Ammonia Ligase* ; Glutamic Acid* ; Glutamine* ; Hippocampus* ; Rats*

The purpose of this study was to determine the effect of regular exercise during dexamethasone injection in the body weight, weight of hind-limb muscles, myofibrillar protein content and glutamine synthetase activity. 180-200g female Wistar were divided into four groups: control, exercise, dexamethasone injection(dexa), and exercise during dexamethasone injection(D+E) group. The dexa group received daily subcutaneous injection of dexamethasone at a dose of 4mg/kg body weight for 7days. The exercise group ran on a treadmill for 60min/day(20minutes every 4 hours) at 10m/min and a 10degrees grade. The control group received daily subcutaneous injection of normal saline at a dose of 4mg/kg body weight for 7 days. The D+E group ran on a treadmill for 60min/day(20minutes every 4 hours) at 10m/min and a 10degrees grade during dexamethasone injection. Body weight of the control group increased significantly from days of experiment, that of the dexa group decreased significantly from day 4 of the dexa group decrease significantly from day 4 of the experiment resulting in a 82.4% decrease compared to the first day of the experiment. Body weight of the D+E group decrease significantly from day 5 of experiment resulting in a 81.77% decrease compared to the first day of the experiment. Body weights, muscle weight and myofibrillar protein content of the plantaris and gastrocnemius decrease significantly and muscle weight of the sleys tended to decrease with dexamethasone injection. Glutamine synthetase activity of the hind-limb muscles increase significantly with the dexamethasone injection. The relative weight of the soleus was comparable to the control group and that of plantaris decrease significantly and that of gastrocnemius tended to decrease compared to that of the control in the dexa group. Body weight and muscle weight of the plantaris and gastronemius of the exercise group were comparable to the control group, and the muscle weight of soleus showed a tendency to increase. The relative weight of the soleus increased significantly and that of the plantaris and gastrocnemius were comparable to the control in the exercise group. Myofibrillar protein content of the soleus and plantaris increased significantly and there was no change of GS activity of the hind-limb muscles compared to the control in the exercise group. Body weight of the D+E group was comparable to the dexa group, muscle weight of the hind-limb muscles increased significantly. Myofibrillar protein content of the soleus and plantaris increase significantly and that of the gastrocnemius tendency to increase compared to the dexa group. Body weight and muscle weight of the plantaris and gastrocnemius of the D+E group did not recover to that of the control group. Muscle weight of the soleus recovered to that of the control group. The relative weight and myofibrillar protein content of the hind-limb muscles recovered to that of the control group. From these results, it is suggested that regular exercise during dexamethasone injection might attenuate the muscle atrophy of the hind-limb muscles.
Animals ; Body Weight ; Dexamethasone* ; Female ; Glutamate-Ammonia Ligase ; Humans ; Injections, Subcutaneous ; Muscles ; Muscular Atrophy ; Rats*

Nitrogen is one of the most important nutrient elements for plants and a major limiting factor in plant growth and crop productivity. Glutamine synthase (GS) is a key enzyme involved in the nitrogen assimilation and recycling in plants. So far, members of the glutamine synthase gene family have been characterized in many plants such as Arabidopsis, rice, wheat, and maize. Reports show that GS are involved in the growth and development of plants, in particular its role in seed production. However, the outcome has generally been inconsistent, which are probably derived from the transcriptional and post-translational regulation of GS genes. In this review, we outlined studies on GS gene classification, QTL mapping, the relationship between GS genes and plant growth with nitrogen and the distribution characters, the biological functions of GS genes, as well as expression control at different regulation levels. In addition, we summarized the application prospects of glutamine synthetase genes in enhancing plant growth and yield by improving the nitrogen use efficiency. The prospects were presented on the improvement of nitrogen utility efficiency in crops and plant nitrogen status diagnosis on the basis of glutamine synthase gene regulation.
Arabidopsis ; Genes, Plant ; Glutamate-Ammonia Ligase ; genetics ; Nitrogen ; metabolism ; Oryza ; Plants ; enzymology ; genetics ; Triticum ; Zea mays

Glufosinate ammonium is the active ingredient in broad-spectrum contact herbicides such as BASTA(R) that inhibits the activity of glutamine synthetase, which is necessary for the production of the amino acid glutamine and for ammonia detoxification. Complications of glufosinate ammonium intoxication include gastrointestinal symptoms, loss of consciousness, convulsions, memory impairment, respiratory failure, and cardiovascular instability. We report herein a case of encephalopathy and reversible signal changes in the splenium of the corpus callosum, the bilateral corticospinal tracts, the hippocampi, and the cerebellar peduncles as seen in diffusion-weighted magnetic resonance imaging and fluid-attenuated inversion recovery images following BASTA(R) intoxication.
Ammonia ; Ammonium Compounds* ; Corpus Callosum ; Glutamate-Ammonia Ligase ; Glutamine ; Herbicides ; Magnetic Resonance Imaging ; Memory ; Pyramidal Tracts ; Respiratory Insufficiency ; Seizures ; Unconsciousness