Citric Acid Cycle ; Citric Acid ; Malates/metabolism* ; Citrates/metabolism* ; Aspartic Acid/metabolism*

OBJECTIVE: To clarify the functional effects of differential expression of ring finger and tryptophan-aspartic acid 2 (RFWD2) on dendritic development and formation of dendritic spines in cerebral cortex neurons of mice. METHODS: Immunofluorescent staining was used to identify the location and global expression profile of RFWD2 in mouse brain and determine the co-localization of RFWD2 with the synaptic proteins in the cortical neurons. We also examined the effects of RFWD2 over-expression (RFWD2-Myc) and RFWD2 knockdown (RFWD2-shRNA) on dendritic development, dendritic spine formation and synaptic function in cultured cortical neurons. RESULTS: RFWD2 is highly expressed in the cerebral cortex and hippocampus of mice, and its expression level was positively correlated with the development of cerebral cortex neurons and dendrites. RFWD2 expression was detected on the presynaptic membrane and postsynaptic membrane of the neurons, and its expression levels were positively correlated with the length, number of branches and complexity of the dendrites. In cultured cortical neurons, RFWD2 overexpression significantly lowered the expressions of the synaptic proteins synaptophysin (P < 0.01) and postsynapic density protein 95 (P < 0.01), while RFWD2 knockdown significantly increased their expressions (both P < 0.05). Compared with the control and RFWD2-overexpressing cells, the neurons with RFWD2 knockdown showed significantly reduced number of dendritic spines (both P < 0.05). CONCLUSION RFWD2 can regulate the expression of the synaptic proteins, the development of the dendrites, the formation of the dendritic spines and synaptic function in mouse cerebral cortex neurons through ubiquitination of Pea3 family members and c-Jun, which may serve as potential treatment targets for neurological diseases.
Animals ; Aspartic Acid/metabolism* ; Cerebral Cortex ; Dendritic Spines/metabolism* ; Mice ; Neurons/metabolism* ; Synapses ; Tryptophan/metabolism*

Localized, water-suppressed in vivo 'H MRS was performed to evaluated the proton metabolic alterations in patients with acute cerebral infarction.Ten brain infarction patients(six males and four females; age range 53-77) participated in this study. GE Signa 1.5-T whole-body NMI/MRS system using STEAM pulse sequence was used. Voxels were selected from the cerebral infarcted region and contralateral normal region as control in the same patient. Proton metaboliteratiosrelativetocreatine (Cr) wereobtainedusingaMa-rquartalgorithm. The specific features in the cerebral infarcted regions demonstrated a significant decrease of N-acetyl aspartate (NAA)/creatine (Cr) ratio, compared with control regions. Markedly increased lactate (Lac) level was observed in areas of cerebral infarctioln in all patients. Our preliminary study showed that NAA/Cr ratio in the infarcted regions was substanially different from that in control regions.The signal intensity of Lac may be served as a metabolic criterion that can specify acuteness of infarction, and also evaluate the therapeutic effect. It is necessary to investigate the spectral alterations in various stages of cerebral infarction for further detail analysis.
Aspartic Acid ; Brain Infarction ; Cerebral Infarction* ; Female ; Humans ; Infarction ; Lactic Acid ; Male ; Metabolism ; Protons ; Steam

Glutinous rice wine is a traditional food in south of China and it can coagulate milk. It has been proved that its function of coagulating milk is because of the presence of milk-clotting enzyme produced by microorganisms in glutinous rice wine. The aim of this work is to isolate milk-clotting enzyme producing strain from glutinous rice wine and study the fermentation condition. We screened out four bacteria and fungus by gradient dilution. It was proved that mold played the most important role in the production of milk-clotting enzyme. This is further confirmed by casein plate method. The optimization of fermentation conditions revealed that two times concentrated potato medium supplemented with 5% glucose without additional nitrogen was better for production of the enzyme. The enzyme activity was increased 144% under the conditions established.
Aspartic Acid Endopeptidases ; biosynthesis ; Bacteria ; isolation & purification ; metabolism ; Culture Media ; Fermentation ; Oryza ; metabolism ; Wine ; microbiology ; Yeasts ; cytology ; isolation & purification ; metabolism

To understand the neurochemical mechanisms underlying the vestibular compensation, we determined the levels of amino acids such as aspartate, glutamate, glutamine, glycine, taurine, alanine in the medial vestibular nucleus (MVN) following unilateral labyrinthectomy (UL), by using in vivo brain microdialysis and high-performance liquid chromatography technique. Rats were pretreated by infusing 2% lidocaine 1.2 mL or 10 mg arsanilic acid into the tympanic cavity to obstruct uni-periphery vestibular organ, and then the levels of amino acids were determined in MVN of normal control and ipsilateral or contralateral lesional (ipsi-/contra-lesional) rats. In the control experiment, the levels of aspartate, glutamate, glutamine, glycine, taurine, and alanine were (6.15 +/- 0.59), (18.13 +/- 1.21), (33.73 +/- 1.67), (9.26 +/- 0.65), (9.56 +/- 0.77) and (10.07 +/- 0.83) pmol/8 muL sample, respectively. The concentrations of aspartate and glutamate decreased, while the concentration of taurine increased in the ipsi-lesional MVN of rats 10 min after infusing 2% lidocaine into middle ear to obstruct uni-periphery vestibular organ. Whereas the concentration of glutamate increased, the concentrations of glycine and alanine decreased in the contra-lesional MVN, accompanied by imbalances of glutamate, glycine and alanine in the bilateral nuclei. In contrast, the levels of glutamate and alanine decreased, the level of glutamine increased in the ipsi-lesional MVN, and the level of glutamate decreased in the contra-lesional MVN of rats 2 weeks after infusing 10 mg arsanilic acid into the tympanic cavity to obstruct uni-periphery vestibular organ. Furthermore, the level of glutamine in the ipsi-lesional MVN was obviously higher than that in the contra-lesional MVN. These results demonstrate that an imbalance of different amino acids appeared in bilateral MVN after UL, and this imbalance decreased after the development of vestibular compensation. Whereas the imbalance of glutamine release in bilateral nuclei appeared after vestibular compensation.
Amino Acids ; metabolism ; Animals ; Aspartic Acid ; metabolism ; Ear, Inner ; physiology ; surgery ; Glutamic Acid ; metabolism ; Male ; Rats ; Rats, Wistar ; Taurine ; metabolism ; Vestibular Nuclei ; metabolism ; physiopathology

We report the clinical and MR manifestations of an 18 year-old girl with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Recurrent status epilepticus caused reversible cytotoxic edema on diffusion-weighted images (DWI). Initial and one month follow-up MR spectroscopy, after seizure control, showed some discrepancies in the ratio of metabolites. N-acetylaspartate (NAA) partially recovered (NAA/creatine (Cr) ratio: 1.27-->1.84). This was because of a normalization of decreased NAA due to cellular dysfunction as a result of status epilepticus. A low ratio of NAA/Cr due to abnormal mitochondria remained in the decreased state. Reversible NAA/Cr ratios in the acute lesion suggested that NAA reflects the neuronal function as well as the level of neuronal structural damage. The altered NAA/Cr ratio better correlated with the abnormal signal intensity area of T2-weighted images (T2WI) and DWI than the lactate (Lac)/Cr ratio. With conservative treatment with anti-epileptics not accompanied by coenzyme Q or sodium dichloroacetate, lactate persistently increased (Lac/Cr ratio: 1.01-->1.21) because of the continued production of lactate in cells with respiratory deficiency, which is the main pathology of MELAS.
Adolescence ; Aspartic Acid/metabolism ; Aspartic Acid/analogs & derivatives* ; Brain/metabolism ; Case Report ; Creatine/metabolism ; Diffusion ; Female ; Human ; MELAS Syndrome/metabolism ; MELAS Syndrome/diagnosis* ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy

OBJECTIVETo explore the effects of 1,2-dichloroethane (1,2-DCE) on the behavior and the brain neurotransmitter levels in mice.

METHODSThirty mice were randomly divided into four groups, which were control group and groups of low, middle and high exposure (225, 450 and 900 mg/m3) to 1,2-DCE for 10 days (3.5 h a day) by inhalation. After the last exposure, the open field test was performed immediately. After exposure all mice were killed and the brain tissues were taken up rapidly. The levels of aspartate (Asp), glutamate (Glu) and gamma-aminobutyric acid (GABA) in the brain were detected by high performance liquid chromatography (HPLC).

RESULTSLevels of Asp and Glu in all exposure groups increased with doses. As compared to the control group, levels of Glu in all exposure groups increased significantly (P < 0.05). Levels of GABA in the low exposure group were significantly lower than those in control group, but those in the high exposure group were significantly higher than those in control group. The results of the open field test showed that effect of low exposure to 1,2-DCE on the behavior was stimulant, but the high exposure to 1,2-DCE inhibited behavior of exploration, excitement and sport.

CONCLUSIONSSubacute exposure to 1,2-DCE could result in the change of amino acid neurotransmitter content and ratio in the brain, thereby change the behavior of mice appeared, which might be the mechanism of neurotoxicity caused by 1,2-DCE in part.

Animals ; Aspartic Acid ; analysis ; Behavior, Animal ; drug effects ; Brain ; metabolism ; Ethylene Dichlorides ; toxicity ; Female ; Glutamic Acid ; analysis ; Mice ; Mice, Inbred Strains ; Neurotransmitter Agents ; metabolism ; gamma-Aminobutyric Acid ; analysis

BACKGROUNDIn vivo proton magnetic resonance spectroscopy (MRS) provides a noninvasive method of examining a wide variety of cerebral metabolites in both healthy subjects and patients with various brain diseases. Absolute metabolite concentrations have been determined using external and internal standards with known concentrations. When an external standard is placed beside the head, variations in signal amplitudes due to B1 field inhomogeneity and static field inhomogeneity may occur. Hence an internal standard is preferable. The purpose of this study was to quantitatively analyze the metabolite concentrations in normal adult brains and gliomas by in vivo proton MRS using the fully relaxed water signal as an internal standard.

METHODSBetween January 1998 and October 2001, 28 healthy volunteers and 16 patients with gliomas were examined by in vivo proton MRS. Single-voxel spectra were acquired using the point-resolved spectroscopic pulse sequence with a 1.5 T scanner (TR/TE/Ave = 3000 ms/30 ms/64).

RESULTSThe calculated concentrations of N-acetyl-asparatate (NAA), creatine (Cre), choline (Cho), and water (H2O) in the normal hemispheric white matter were (23.59 +/- 2.62) mmol/L, (13.06 +/- 1.8) mmol/L, (4.28 +/- 0.8) mmol/L, and (47,280.96 +/- 5414.85) mmol/L, respectively. The metabolite concentrations were not necessarily uniform in different parts of the brain. The concentrations of NAA and Cre decreased in all gliomas (P < 0.001). The ratios of NAA/Cho and NAA/H2O showed a significant difference between the normal brain and gliomas, and also between the high and low grades (P < 0.001).

CONCLUSIONSQuantitative analysis of in vivo proton MR spectra using the fully relaxed water signal as an internal standard is useful. The concentrations of NAA and the ratios of NAA/H2O and NAA/Cho conduce to discriminating between the glioma and normal brain, and also between the low-grade glioma and high-grade glioma.

Adult ; Aspartic Acid ; analogs & derivatives ; metabolism ; Brain ; metabolism ; Choline ; metabolism ; Creatine ; metabolism ; Female ; Glioma ; metabolism ; Glycine ; metabolism ; Humans ; Inositol ; metabolism ; Magnetic Resonance Spectroscopy ; Male

OBJECTIVE: To explore the amino acid metabolomics characteristics of myeloid-derived suppressor cells (MDSCs) in mice with sepsis induced by the cecal ligation and puncture (CLP). METHODS: The sepsis mouse model was prepared by CLP, and the mice were randomly divided into a sham operation group (sham group, n = 10) and a CLP model group (n = 10). On the 7th day after the operation, 5 mice were randomly selected from the surviving mice in each group, and the bone marrow MDSCs of the mice were isolated. Bone marrow MDSCs were separated to measure the oxygen consumption rate (OCR) by using Agilent Seahorse XF technology and to detect the contents of intracellular amino acids and oligopeptides through ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) technology. Different metabolites and potential biomarkers were analyzed by univariate statistical analysis and multivariate statistical analysis. The major metabolic pathways were enriched using the small molecular pathway database (SMPDB). RESULTS: The proportion of MDSCs in the bone marrow of CLP group mice (75.53% ± 6.02%) was significantly greater than that of the sham group (43.15%± 7.42%, t = 7.582, P < 0.001), and the basal respiratory rate [(50.03±1.20) pmol/min], maximum respiration rate [(78.07±2.57) pmol/min] and adenosine triphosphate (ATP) production [(25.30±1.21) pmol/min] of MDSCs in the bone marrow of CLP group mice were significantly greater than the basal respiration rate [(34.53±0.96) pmol/min, (t = 17.41, P < 0.001)], maximum respiration rate [(42.57±1.87) pmol/min, (t = 19.33, P < 0.001)], and ATP production [(12.63±0.96) pmol/min, (t = 14.18, P < 0.001)] of sham group. Leucine, threonine, glycine, etc. were potential biomarkers of septic MDSCs (all P < 0.05). The increased amino acids were mainly enriched in metabolic pathways, such as malate-aspartate shuttle, ammonia recovery, alanine metabolism, glutathione metabolism, phenylalanine and tyrosine metabolism, urea cycle, glycine and serine metabolism, β-alanine metabolism, glutamate metabolism, arginine and proline metabolism. CONCLUSION The enhanced mitochondrial oxidative phosphorylation, malate-aspartate shuttle and alanine metabolism in MDSCs of CLP mice may provide raw materials for mitochondrial aerobic respiration, thereby promoting the immunosuppressive function of MDSCs. Blocking the above metabolic pathways may reduce the risk of secondary infection in sepsis and improve the prognosis.
Adenosine Triphosphate/metabolism* ; Alanine/metabolism* ; Animals ; Aspartic Acid/metabolism* ; Biomarkers/metabolism* ; Chromatography, Liquid ; Glycine/metabolism* ; Malates/metabolism* ; Mice ; Myeloid-Derived Suppressor Cells/metabolism* ; Sepsis/complications* ; Tandem Mass Spectrometry

OBJECTIVE: To detect metabolic changes of bilateral frontal lobe in patients with multiple system atrophy (MSA) and cognitive dysfunction by 1H-proton magnetic resonance spectroscopy (1H-MRS).
 METHODS: N-acetylaspartate (NAA)/creatine(Cr), choline (Cho)/Cr, myoinositol (mI)/Cr in three sides of frontal lobe were detected by 1H-MRS in 48 healthy controls, 23 patients with MSA and cognitive dysfunction and 19 patients with MSA but without cognitive dysfunction.
 RESULTS: NAA/Cr of bilateral frontal lobes in patients with MSA and cognitive dysfunction was significantly decreased compared with MSA patients without cognitive dysfunction and healthy controls (P<0.05). mI/Cr of right frontal lobes was significantly increased in patients with MSA and cognitive dysfunction compared with healthy controls (P<0.05). There was a negative correlation between NAA/Cr of bilateral frontal lobes and duration while a positive correlation between NAA/Cr of bilateral frontal lobes and MoCA score in patients with MSA and cognitive dysfunction.
 CONCLUSION There is a decrease in NAA/Cr and an increase in mI/Cr in frontal lobes in patients with MSA and cognitive dysfunction, which may be associated with cognitive dysfunction in MSA patients.
Aspartic Acid ; analogs & derivatives ; metabolism ; Choline ; metabolism ; Cognition Disorders ; physiopathology ; Creatine ; metabolism ; Frontal Lobe ; metabolism ; Humans ; Inositol ; metabolism ; Multiple System Atrophy ; physiopathology ; Proton Magnetic Resonance Spectroscopy