Relación estructura-función de la enzima uroporfirinógeno descarboxilasa: implicancias para la comprensión y el tratamiento de la porfiria cutánea tarda / Structure-function relationship of the enzyme uroporphyrinogen decarboxylase: implications for the understanding and treatment of porphyria cutanea tarda / Relação estrutura-função da enzima uroporfirinogênio descarbioxilase: implicações para a compreensão e tratamento da porfiria cutânea tardia / Reconocimiento a la trayectoria del Prof. Dr. Juan Miguel Castagnino†

Resumen La uroporfirinógeno descarboxilasa humana (UROD-h) es la quinta enzima del camino biosintético del hemo y su actividad deficiente, relacionada a mutaciones en su gen, se encuentra asociada a un subgrupo de porfirias. El objetivo de este trabajo fue estudiar la relación entre la dimerización de la enzima y su actividad enzimática y comprobar si la dimerización de UROD-h es imprescindible tanto para la primera etapa de la reacción (urogen→heptagen), como para la segunda etapa (heptagen→coprogen). Con ese objetivo, se expresó y purificó la UROD-h hasta homogeneidad, se analizó el comportamiento dímero-monómero bajo distintas condiciones que pudieran desplazar el equilibrio de dimerización y se evaluó la actividad enzimática en dichas condiciones. Los resultados obtenidos sugieren que la especie activa para la primera etapa de la reacción es el homodímero y que tanto el dímero como el monómero se comportan como especies activas para la segunda etapa de la reacción. Se propone que mutaciones clínicas como la Y311C, existentes en pacientes con porfiria cutánea tarda, podrían afectar la estabilidad del dímero y podrían ser el blanco para futuras terapias génicas.

Abstract Human uroporphyrinogen decarboxylase (UROD-h) is the fifth enzyme in the heme biosynthetic pathway and its deficient activity, related to mutations in its gene, is associated with a subset of porphyrias. The objective of this work was to study the relationship between the dimerisation of the enzyme and its enzymatic activity and to verify if the dimerisation of UROD-h is essential both for the first stage of the reaction (urogen→heptagen), and for the second stage (heptagen→ coprogen). With this objective, the UROD-h was expressed and purified to homogeneity, the dimer- monomer behaviour was analysed under different conditions, which could shift the dimerisation equilibrium, and the enzymatic activity was evaluated under these conditions. The results obtained suggest that the active species for the first stage of the reaction is the homodimer, and both the dimer and the monomer behaved as active species for the second stage of the reaction. It is proposed that clinical mutations such as Y311C, existing in porphyria cutanea tarda patients, could affect dimer stability and could be the target of future gene therapies.

Resumo A enzima uroporfirinogênio descarboxilase humana (UROD-h) é a quinta enzima da via biossintética do heme e sua atividade deficiente, relacionada com mutações em seu gene, está associada a um subgrupo de porfirias. O objetivo deste trabalho foi estudar a relação entre a dimerização da enzima e sua atividade enzimática e comprovar se a dimerização da UROD-h é imprescindível tanto para a primeira etapa da reação (urogênio→heptagênio), quanto para a segunda etapa (heptagênio→coprogênio). Com esse objetivo, a UROD-h foi expressa e purificada até a homogeneidade, o comportamento de dímero-monômero foi analisado sob diversas condições, que puderam deslocar o equilíbrio de dimerização, e a atividade enzimática foi avaliada em tais condições. Os resultados obtidos sugerem que a espécie ativa para a primeira etapa da reação é o homodímero, e tanto o dímero quanto o monômero se comportam como espécies ativas para a segunda etapa da reação. Propõe-se que mutações clínicas como Y311C, existentes em pacientes com porfiria cutânea tardia, poderiam afetar a estabilidade do dímero e poderiam ser o alvo de futuras terapias gênicas em porfiria cutânea tardia.

Effects of Yudian Decoction （愈癫汤） on the Metabolic Balance of Glu/GABA in the Brain Tissue of Schizophrenia Model Rats / 中医杂志

ObjectiveTo explore the possible mechanism of Yudian Decoction （愈癫汤） in the treatment of schizophrenia. MethodTwenty male offspring from 5 normal female 17-day-pregnant SD rats were selected as blank group. Fifteen female 17-day-pregnant SD rats were injected intraperitoneally with methyl azomethine acetate （MAM） 25 mg/kg， and the male offspring simulated the neurodevelopmental abnormality to establish a rat model of schizophrenia. Sixty successfully-modeled rats were randomly divided into 20 rats in the model group， 20 rats in the Yudian Decoction group and 20 risperidone group. After 3 days of adaptive cage feeding， the rats in the Yudian Decoction group were gavaged with 1.54 g/（kg·d） of Yudian Decoction， the risperidone group was gavaged with 0.24 mg/（kg·d） of risperidone capsule， while the blank group and the model group were gavaged with 6.7 ml/（kg·d） of distilled water， once a day， for 14 consecutive days. Sample was collected on the day after the last gavage. The expression of glutamate receptor （GluR） and γ-aminobutyric acid receptor subunit α1 （GABAARα1）-positive neurons in the hippocampus and prefrontal cortex were detected by immunofluorescence， and the positive rate was calculated； the expression of small clear proteins （PVs） in the hippocampal CA1 region and the medial prefrontal cortex was detected by immunohistochemistry； The expression of glutamic acid decarboxylase 65 （GAD65） and glutamic acid decarboxylase 67 （GAD67） proteins and mRNAs in the hippocampus and prefrontal cortex were detected by immunoblotting and reverse transcription PCR. ResultCompared with the blank group， the positive rate of GluR in hippocampal area and prefrontal cortex of rats in the model group increased， the positive rate of GABAARα1 in hippocampal area decreased， the PV optical density value in hippocampal CA1 area and medial prefrontal cortex decreased， and the expression of GAD65， GAD67 proteins and mRNA in hippocampal area and prefrontal cortex decreased （P＜0.05 or P＜0.01）. Compared with the model group， GluR positivity rate in hippocampus and prefrontal cortex of risperidone group and Yudian Decoction decreased， GABAARα1 positivity rate in hippocampus increased， PV optical density value in hippocampus CA1 area and medial prefrontal cortex increased， and GAD65， GAD67 proteins and mRNA expression in hippocampus and prefrontal cortex increased （P＜0.05 or P＜0.01）. Compared with the risperidone group， the positive rate of GluR in hippocampus and prefrontal cortex and GABAARα1 in hippocampus in the Yudian Decoction group was reduced， the PV optical density value of hippocampal CA1 area was increased， the protein and mRNA expression of GAD67 in hippocampus area was elevated， and the protein expression of GAD65 in prefrontal cortex was reduced （P＜0.05）. ConclusionYudian Decoction may improve the pathological process of schizophrenia by regulating key regulators of glutamate/γ-aminobutyric acid （Glu/GABA） metabolic balance in the hippocampus and prefrontal cortex and maintaining the balance between neuronal excitation and inhibition.

Progressive encephalomyelitis with rigidity and myoclonus: a case report / 中华神经科杂志

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a specific subtype of the stiff-person syndrome, which is rare and difficult to diagnose clinically. A case of PERM in a 66-year-old female with a fluctuating progressive course was reported in this article. She had increased facial muscle tone, pruritus and sensory hypersensitivity mainly in the head and neck, medullary involvement syndrome and bilateral lower limb rigidity as the main clinical manifestations, and a previous history of pulmonary malignancy, thymoma, typeⅠ diabetes and Hashimoto′s thyroiditis. The patient′s serum and cerebrospinal fluid were positive for anti-glutamic acid decarboxylase antibody. The electromyogram showed a large number of motor unit potentials in the trunk and proximal extremities in the quiet state, which were significantly enhanced during spastic episodes, consistent with the electromyographic manifestations of stiff-person syndrome. The final diagnosis was PERM, and immunotherapy including gamma globulin and hormone responded well. PERM is a rare neurological autoimmune disease with atypical early symptoms, which can be easily misdiagnosed, and it requires attention to avoid delaying the diagnosis.

Improvement effects of aucubin on ADHD-like behaviors in mice via the inhibition of excessive astrocytic activation / 中华行为医学与脑科学杂志

Objective:To investigate the effect of aucubin on behaviors and excessive activation of astrocytic in attention deficit/hyperactivity disorder (ADHD) model mice.Methods:Twelve wild-type C57BL/6 pregnant mice (female, clean grade) were intraperitoneally administered with esketamine (15 mg/kg) to establish an ADHD model in offspring mice. The offspring mice were divided into control+ saline group, control+ aucubin group, Ketamine+ saline group and Ketamine+ aucubin group according to the nest matching principle with 15 in each group.At 14 days after birth, mice in the control+ aucubin group and Ketamine+ aucubin group were administered with aucubin (5 mg/kg, once a day) by gavage for 5 days. Mice in control+ saline group and Ketamine+ saline group were administered with equal volume of 0.9% sodium chloride solution. The offspring mice were housed with their mothers in the same cage until 21 days after birth. Twenty-one days after birth, the offspring mice were evaluated by open field test and elevated plus maze tests. Immunofluorescence assay was used to detect the expression of glutamate decarboxylase 2 (GAD2), γ- aminobutyric acid (GABA) and glial fibrillary acidic protein (GFAP) in the amygdala. The morphological changes of astrocytes were quantitatively analyzed by Sholl analysis. GraphPad Prim 9.0.1 software was used for statistical analysis. The comparison of multiple groups was conducted by one-way ANOVA or Kruskal-Wallis test.Results:(1)The results of behavioral experiments showed that the total distance traveled in the open field test and the residence time in open arm of the elevated plus maze were statistically significant ( F=236.90, H=39.92, both P<0.001). The total distance ((7 044±249)mm, (22 891±2 175)mm, P<0.05) and the residence time in open arm(12.69(9.86, 17.24)s, 2.72(0.57, 3.87)s, P<0.05) of mice in Ketamine+ saline group were both higher than those in control+ saline group.The total distance((22 891±2 175)mm, (8 252±839)mm, P<0.05) and the the residence time in open arm(5.45(1.13, 10.99)s, 12.69(9.86, 17.24)s, P<0.05) of Ketamine+ aucubin group were both lower than those of Ketamine+ saline group.(2)The immunofluorescence results showed that the levels of GAD2, GABA and GFAP intensity in amygdala of mice in the four groups were statistically significant ( F=145.50, 50.08, 53.83, all P<0.05). Compared with control+ saline group, the fluorescence intensities of GAD2 ((100.00±9.60)%, (24.86±4.14)%, P<0.05) and GABA ((100.00±16.84))%, (25.48±5.70)%, P<0.05) of Ketamine+ saline group were down-regulated, and the GFAP((100.00±18.02)%, (223.80±25.85)%, P<0.05) was up-regulated. Compared with Ketamine+ saline group, the fluorescence intensities of GAD2 ((24.86±4.14)%, (56.08±6.55)%, P<0.05) and GABA((25.48±5.70)%, (52.59±15.74)%, P<0.05) in Ketamine+ aucubin group were up-regulated, but the fluorescence intensity of GFAP ((223.80±25.85)%, (157.10±22.10)%, P<0.05) was down-regulated.(3)Sholl analysis indicated that the number of the intersections between the astrocyte processes or the branches of astrocyte processes was statistically significant in the 4 groups ( F=12.47, P<0.05). Compared with control+ saline group, the number of the intersections in Ketamine+ saline group((2.07±0.48), (1.67±0.72), P<0.05) increased. While the number of the intersections in Ketamine+ aucubin group was lower than that of Ketamine+ saline group ((1.20±0.78), (2.07±0.48), P<0.05). Conclusion:Aucubin administration can alleviate ADHD-like behaviors in offspring mice, and the mechanism may be associated with the inhibition of excessive astrocytic activation.

Efficient biosynthesis of γ-aminobutyric acid by rationally engineering the catalytic pH range of a glutamate decarboxylase from Lactobacillus plantarum / 生物工程学报

γ-aminobutyric acid can be produced by a one-step enzymatic reaction catalyzed by glutamic acid decarboxylase. The reaction system is simple and environmentally friendly. However, the majority of GAD enzymes catalyze the reaction under acidic pH at a relatively narrow range. Thus, inorganic salts are usually needed to maintain the optimal catalytic environment, which adds additional components to the reaction system. In addition, the pH of solution will gradually rise along with the production of γ-aminobutyric acid, which is not conducive for GAD to function continuously. In this study, we cloned the glutamate decarboxylase LpGAD from a Lactobacillus plantarum capable of efficiently producing γ-aminobutyric acid, and rationally engineered the catalytic pH range of LpGAD based on surface charge. A triple point mutant LpGADS24R/D88R/Y309K was obtained from different combinations of 9 point mutations. The enzyme activity at pH 6.0 was 1.68 times of that of the wild type, suggesting the catalytic pH range of the mutant was widened, and the possible mechanism underpinning this increase was discussed through kinetic simulation. Furthermore, we overexpressed the Lpgad and LpgadS24R/D88R/Y309K genes in Corynebacterium glutamicum E01 and optimized the transformation conditions. An optimized whole cell transformation process was conducted under 40 ℃, cell mass (OD600) 20, 100 g/L l-glutamic acid substrate and 100 μmol/L pyridoxal 5-phosphate. The γ-aminobutyric acid titer of the recombinant strain reached 402.8 g/L in a fed-batch reaction carried out in a 5 L fermenter without adjusting pH, which was 1.63 times higher than that of the control. This study expanded the catalytic pH range of and increased the enzyme activity of LpGAD. The improved production efficiency of γ-aminobutyric acid may facilitate its large-scale production.

Establishment and characterization of bone marrow mesenchymal stem cell lines stably synthesizing high-level dopamine / 生物工程学报

A triple-transgenic (tyrosine hydroxylase/dopamine decarboxylase/GTP cyclohydrolase 1, TH/DDC/GCH1) bone marrow mesenchymal stem cell line (BMSCs) capable of stably synthesizing dopamine (DA) transmitters were established to provide experimental evidence for the clinical treatment of Parkinson's disease (PD) by using this cell line. The DA-BMSCs cell line that could stably synthesize and secrete DA transmitters was established by using the triple transgenic recombinant lentivirus. The triple transgenes (TH/DDC/GCH1) expression in DA-BMSCs was detected using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and immunofluorescence. Moreover, the secretion of DA was tested by enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). Chromosome G-banding analysis was used to detect the genetic stability of DA-BMSCs. Subsequently, the DA-BMSCs were stereotactically transplanted into the right medial forebrain bundle (MFB) of Parkinson's rat models to detect their survival and differentiation in the intracerebral microenvironment of PD rats. Apomorphine (APO)-induced rotation test was used to detect the improvement of motor dysfunction in PD rat models with cell transplantation. The TH, DDC and GCH1 were expressed stably and efficiently in the DA-BMSCs cell line, but not expressed in the normal rat BMSCs. The concentration of DA in the cell culture supernatant of the triple transgenic group (DA-BMSCs) and the LV-TH group was extremely significantly higher than that of the standard BMSCs control group (P < 0.000 1). After passage, DA-BMSCs stably produced DA. Karyotype G-banding analysis showed that the vast majority of DA-BMSCs maintained normal diploid karyotypes (94.5%). Moreover, after 4 weeks of transplantation into the brain of PD rats, DA-BMSCs significantly improved the movement disorder of PD rat models, survived in a large amount in the brain microenvironment, differentiated into TH-positive and GFAP-positive cells, and upregulated the DA level in the injured area of the brain. The triple-transgenic DA-BMSCs cell line that stably produced DA, survived in large numbers, and differentiated in the rat brain was successfully established, laying a foundation for the treatment of PD using engineered culture and transplantation of DA-BMSCs.

Oromandibular Dystonia is a Prominent Feature in Patients with Aromatic L-Amino Acid Decarboxylase (AADC) Deficiency

Abstract Aromatic L-Amino acid decarboxylase (AADC) deficiency is a rare neurometabolic disorder due to a homozygous or compound heterozygous pathogenic variant of the DDC gene, resulting in low synthesis of the biogenic amines dopamine, serotonin, epinephrine, and norepinephrine. Most patients had severe expression of the disease with global developmental delay, early hypotonia, movement disorders such as oculogyric crises, tremor, and dystonia. Oromandibular dystonia (OMD) is rarely recognized in patients with AADC deficiency. The aim of this study was to describe OMD in detail in 4 patients with AADC deficiency. OMD occurred in isolated form or in association with oculogyric crises, increasing the difficulty in care patients during the crises. The main form of OMD was tongue dystonia associated with mouth opening dystonia. AADC deficiency must be included in the list of genetic causes of OMD.

Coexisting anti-N-methyl-D-aspartate receptor and anti-glutamic decarboxylase antibody- associated encephalitis after herpes simplex virus encephalitis: a case report / 中华神经科杂志

Herpes simplex virus encephalitis (HSE) is a common form of viral encephalitis, often with a single-phase course. A case of HSE with abnormal mental behavior as the main manifestation, admitted in Peking University Shenzhen Hospital in Octorber 2020, which improved after sufficient antiviral treatment was reported. After 2 months, abnormal mental behavior with memory deterioration recurred. It was considered as anti-N-methyl-D-aspartate receptor antibody combined with anti-glutamic decarboxylase antibody double-positive encephalitis, and improved after rituximab treatment. At present, there is no clinical report of such double antibody positive autoimmune encephalitis secondary to HSE. The purpose of this case report is to raise clinician awareness of post-HSE autoimmune encephalitis.

miRNA-6516-5p regulates the proliferation and migration of renal cancer cells by targeting ODC1 / 国际外科学杂志

Objective:To explore the expression of microRNA (miRNA)-6516-5p in renal cancer cell lines and the molecular mechanisms regulating the proliferation and migration of renal cancer cells.Methods:quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-6516-5p in renal cancer cell lines and normal proximal renal tubular epithelial cell lines. The liposome method was used to transiently transfect miR-6516-5p mimic and nonsense sequence (NC) into renal cancer cells with the lowest expression of miR-6516-5p, namely miR-6516-5p group and NC group. qRT-PCR was used to detect the expression of miR-6516-5p in transfected cells. CCK-8 and Transwell migration experiment were used to detect the proliferation and migration of transfected cells. Bioinformatics software and dual luciferase gene report experiment were used to predict and verify the regulation of miR-6516-5p on target gene, respectively. qRT-PCR and Western blotting were used to detect the expression of target gene in transfected cells. Measurement data were expressed as mean±standard deviation ( ± s), t-test was used for comparison between two groups, and one-way analysis of variance was used for comparison between multiple groups. Results:The expression of miR-6516-5p in renal cancer cell lines was significantly lower than that of normal proximal tubular epithelial cells ( P<0.01), and the expression of miR-6516-5p in 786-O cells was the lowest ( F=27.69, P<0.01). The expression of miR-6516-5p in 786-O cells in NC group and miR-6516-5p group was 1.01±0.08 and 9.91±1.16, respectively. Compared with the NC group, the expression of miR-6516-5p in 786-O cells in the miR-6516-5p group was significantly increased ( t=7.63, P<0.01). Up-regulation of miR-6516-5p can significantly inhibit the proliferation of 786-O cells ( P<0.05). The migration numbers of NC group and miR-6516-5p group were 85.65±8.77 and 28.05±6.20, respectively. Overexpression of miR-6516-5p could inhibit the migration of 786-O cells ( t=5.36, P< 0.01). The target gene of miR-6516-5p may be ornithine decarboxylase 1 ( ODC1), miR-6516-5p can significantly inhibit the luciferase activity of wild-type ODC1-3′UTR ( t=9.83, P<0.01). Up-regulation of miR-6516-5p can reduce the expression of ODC1 mRNA and protein in 786-O cells ( P<0.01). Conclusion:The expression of miR-6516-5p is reduced in renal cancer cell lines, miR-6516-5p inhibits the proliferation and migration of renal cancer 786-O cells by targeting ODC1, miR-6516-5p may become a potential molecular target of renal cancer.

Molecular engineering and immobilization of lysine decarboxylase for synthesis of 1, 5-diaminopentane: a review / 生物工程学报

1, 5-diaminopentane, also known as cadaverine, is an important raw material for the production of biopolyamide. It can be polymerized with dicarboxylic acid to produce biopolyamide PA5X whose performances are comparable to that of the petroleum-based polyamide materials. Notably, biopolyamide uses renewable resources such as starch, cellulose and vegetable oil as substrate. The production process does not cause pollution to the environment, which is in line with the green and sustainable development strategy. The biosynthesis of 1, 5-diaminopentane mainly includes two methods: the de novo microbial synthesis and the whole cell catalysis. Lysine decarboxylase as the key enzyme for 1, 5-diaminopentane production, mainly includes an inducible lysine decarboxylase CadA and a constituent lysine decarboxylase LdcC. Lysine decarboxylase is a folded type Ⅰ pyridoxal-5' phosphate (PLP) dependent enzyme, which displays low activity and unstable structure, and is susceptible to deactivation by environmental factors in practical applications. Therefore, improving the catalytic activity and stability of lysine decarboxylase has become a research focus in this field, and molecular engineering and immobilization are the mainly approaches. Here, the mechanism, molecular engineering and immobilization strategies of lysine decarboxylase were reviewed, and the further strategies for improving its activity and stability were also prospected, with the aim to achieve efficient production of 1, 5-diaminopentane.

Effects of Body Weight-supported Treadmill Training on Neuropathic Pain and Expression of Glutamate Decarboxylase (GAD)-65/67 in Spinal Dorsal Horn of Rats with Spinal Cord Injury / 中国康复理论与实践

Objective:To investigate the effect of body weight-supported treadmill training on neuropathic pain and expression of glutamate decarboxylase-65/67 (GAD-65/67) in spinal dorsal horn of rats with spinal cord injury (SCI). Methods:A total of 24 Sprague-Dawley rats were randomly divided into sham group, SCI-sedentary (SCI-Sed) group and SCI-Exercise (SCI-Ex) group, with eight rats in each group. Allen's method was used to make T10 incomplete SCI model. Seven days after SCI, SCI-Ex group was given body weight-supported treadmill training. Before SCI, and seven days, 14 days, 21 days, 28 days and 35 days after SCI, the von Frey filaments and thermal stimulation pain tester were used to evaluate the mechanical and thermal pain thresholds. Then, Western blotting and immunohistochemical analysis were performed on the spinal cord of all rats to detect the expression of GAD-65 and GAD-67. Results:The mechanical and thermal pain thresholds were higher in SCI-Ex group than in SCI-Sed group 21 days, 28 days and 35 days after SCI (P < 0.01). Compared with the sham group, the expression of GAD-65 and GAD-67 decreased in SCI and SCI-Ex groups (P < 0.05), and increased in SCI-Ex group compared with that of SCI-Sed group (P < 0.05). Conclusion:Body weight-supported treadmill training could increase the synthesis of GAD-65/67 in the distal spinal cord dorsal horn of incomplete SCI rats, and improve the pain thresholds of hind limbs in rats with SCI.

Therapeutic effect of oral vaccine based on glutamate decarboxylase 65 on streptozotocin-induced type 1 diabetic mice / 中国药科大学学报

@#To investigate the therapeutic effect of oral vaccine based on glutamate decarboxylase 65 (GAD65) on streptozotocin (STZ) -induced type 1 diabetic (T1D) mice, the mice model of T1D was established by intraperitoneal injection of low dose multiple STZ. CTB-GADIII encapsulated with calcium alginate (Ca-Alg-GADIII) was formulated using crosslinking technology with sodium alginate and calcium chloride, and was administered intragastric to T1D mice once a week for 5 consecutive weeks.Blood glucose and body weight of the mice were recorded weekly, and pharmacodynamics against T1D of Ca-Alg-GADIII were investigated by glucose tolerance assay (OGTT) and pancreatic histopathological analysis. The levels of glutamic acid decarboxylase antibody (GADA), and insulin autoantibody (IAA) and related cytokines (IL-4, IFN-γ, TGF-β1) in serum were detected by ELISA, and the CD4 + T cell subsets were detected by flow cytometry. The immunological mechanism of oral vaccine against T1D was preliminarily discussed. The results showed that the disease-related indicators improved in immunized mice: fasting blood glucose improved, glucose tolerance and insulin secretion increased, pancreatic injury decreased, autoantibodies like GADA and IAA titers significantly decreased, and CD4 + T cell immune balance in mesenteric lymph node (MLN) and pancreatic lymph node (PLN) improved to some extent. The results suggest that oral vaccine Ca-Alg-GADIII has some therapeutic effect on STZ-induced T1D mice.

Heterogeneous expression of DOPA decarboxylase to improve the production of dopamine in Escherichia coli / 生物工程学报

Dopamine is the precursor of a variety of natural antioxidant compounds. In the body, dopamine acts as a neurotransmitter that regulates a variety of physiological functions of the central nervous system. Thus, dopamine is used for the clinical treatment of various types of shock. Dopamine could be produced by engineered microbes, but with low efficiency. In this study, DOPA decarboxylase gene from Sus scrofa (Ssddc) was cloned into plasmids with different copy numbers, and transformed into a previously developed L-DOPA producing strain Escherichia coli T004. The resulted strain was capable of producing dopamine from glucose directly. To further improve the production of dopamine, a sequence-based homology alignment mining (SHAM) strategy was applied to screen more efficient DOPA decarboxylases, and five DOPA decarboxylase genes were selected from 100 candidates. In shake-flask fermentation, the DOPA decarboxylase gene from Homo sapiens (Hsddc) showed the highest dopamine production (3.33 g/L), while the DOPA decarboxylase gene from Drosophila Melanogaster (Dmddc) showed the least residual L-DOPA concentration (0.02 g/L). In 5 L fed-batch fermentations, production of dopamine by the two engineered strains reached 13.3 g/L and 16.2 g/L, respectively. The residual concentrations of L-DOPA were 0.45 g/L and 0.23 g/L, respectively. Finally, the Ssddc and Dmddc genes were integrated into the genome of E. coli T004 to obtain genetically stable dopamine-producing strains. In 5 L fed-batch fermentation, 17.7 g/L of dopamine was produced, which records the highest titer reported to date.

Targeting autophagy using small-molecule compounds to improve potential therapy of Parkinson's disease

Parkinson's disease (PD), known as one of the most universal neurodegenerative diseases, is a serious threat to the health of the elderly. The current treatment has been demonstrated to relieve symptoms, and the discovery of new small-molecule compounds has been regarded as a promising strategy. Of note, the homeostasis of the autolysosome pathway (ALP) is closely associated with PD, and impaired autophagy may cause the death of neurons and thereby accelerating the progress of PD. Thus, pharmacological targeting autophagy with small-molecule compounds has been drawn a rising attention so far. In this review, we focus on summarizing several autophagy-associated targets, such as AMPK, mTORC1, ULK1, IMPase, LRRK2, beclin-1, TFEB, GCase, ERR

Optimization of a cucurbit6uril-based real-time label-free method for analyzing the activity of ornithine decarboxylase / 生物工程学报

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthetic pathway of polyamines and catalyzes the decarboxylation of ornithine to produce putrescine. Inhibition of ODC activity is a potential approach for the prevention and treatment of many diseases including cancer, as the expression levels and the activities of ODC in many abnormal cells and tumor cells are generally higher than those of normal cells. The discovery and evaluation of ODC inhibitors rely on the monitoring of the reaction processes catalyzed by ODC. There are several commonly used methods for analyzing the activity of ODC, such as measuring the yield of putrescine by high performance liquid chromatography, or quantifying the yield of isotope labelled carbon dioxide. However, the cumbersome operation and cost of these assays, as well as the difficulty to achieve high-throughput and real-time detection, hampered their applications. In this work, we optimized a real-time label-free method for analyzing the activity of ODC based on the macromolecule cucurbit[6]uril (CB6) and a fluorescent dye, DSMI (trans-4-[4-(dimethylamino) styryl]-1-methylpyridinium iodide). Finally, the optimized method was used to determine the activities of different ODC inhibitors with different inhibition mechanisms.

Progress in clinical phenotype and pathogenesis of neuroimmunological diseases associtated with anti-glutamic acid decarboxylase antibody / 中华神经科杂志

Antibodies to glutamic acid decarboxylase (GAD) have been associated with several neurological syndromes, including stiff-person syndrome, cerebellar ataxia and epilepsy. This article critically reviews the main clinical characteristics and the evidence on the pathogenicity of GAD antibodies.

Clinical analysis of nine cases of neuroimmune disease with antibodies against glutamic acid decarboxylase 65 / 中华神经科杂志

Objective:To explore the clinical features, auxiliary examinations, therapies and prognoses of patients with antibodies targeting glutamic acid decarboxylase 65 (GAD65).Methods:The nine patients with anti-GAD65 neuroimmune disease, admitted to Xuanwu Hospital, Capital Medical University from October 2018 to October 2020, were analyzed, retrospectively.Results:The onset age of nine cases was 17-68 (43.6±20.5) years old, and six cases were female. Two cases had preceding infection. The data of initial symptoms were collected and analyzed, including epileptic onset in four cases, memory impairment in two cases, dizziness in two cases and limb stiffness in one case. As the disease continued to advance, one case developed cerebellar ataxia, one case presented with isolated epilepsy, five cases suffered from limbic encephalitis, one case had stiffman syndrome, one case had brainstem encephalitis. Five cases had antibodies against thyroid peroxidase. Brain magnetic resonance imaging scan showed abnormal signals of T 2/fluid attenuated inversion recovery sequences in four cases, mainly involved bilateral temporal lobes or hippocampus. Epileptiform discharges of frontal or temporal regions of electroencephalography were observed in six cases. All cases received immunotherapy and long-term follow-up was performed in seven cases. Four cases benefited from the immunotherapy. Among the four patients, one fully recovered and returned to work, the other three cases developed neurologic sequelae, including seizures (two cases), and short-term memory loss (one case). The remaining three patients were unresponsive to treatment. Conclusions:GAD65 antibody-mediated neuroimmune disease is a rare neurological disorder, presenting with various syndromes including limbic encephalitis or stiffman syndrome, which is more susceptible to young female. The clinical manifestations included epileptic onset, limb stiffness, cognitive impairment and cerebellar ataxia, etc. Detection of GAD65 antibody in serum or cerebrospinal fluid was gold standard. Early immunotherapy contributed to improving the prognosis of patients, especially for those patients with epileptic onset as the main symptom.

Effects of leptin on GABA content and receptor expression in hypothalamus of mice with sleep deprivation / 解放军医学杂志

[Abstract] Objective To observe the effects of the adipocyte hormone leptin on GABA content and receptor expression in hypothalamus of mice with sleep deprivation, and explore the possible mechanisms. Methods Male C57BL/6 mice were randomly divided into three groups (8 each): control group, sleep deprivation (SD) group and leptin supplement (L-SD) group. Mice in control group were set up in a water environment without sleep deprivation, mice in SD group were set up in a "modified multi-platform water environment" to establish a sleep deprivation model, and mice in L-SD group were given leptin 1.3 mg/kg intraperitoneally twice daily in conjunction with sleep deprivation. Seven days after sleep deprivation, the general conditions of mice were observed, body weight was measured and hypothalamic tissues and plasma specimens were collected. ELISA was used to detect the plasma leptin levels, hypothalamic γ-aminobutyric acid (GABA) and glutamate (Glu) contents. Western blotting was performed to detect the expression levels of GABA key glutamate decarboxylase 67 (GAD67) and GABAA receptor α1 subtype protein (GABAARα1). Results Compared with control group, the weight of mice in SD group significantly reduced [(22.03±0.42) g vs. (17.75±0.75) g, P0.05). The hypothalamic Glu levels were obviously higher in SD group [(686.56±10.01) ng/g] and L-SD group [(668.64+9.93) ng/g] than that in control group [(577.11±16.36) ng/g] (P0.05). The expressive levels of GAD67 and GABAARα1 protein in the hypothalamus of mice in SD group [0.68±0.06, 0.69±0.07] were significantly lower than that in control group (1.09±0.13, 0.99±0.07) (P<0.05); While the expressive levels of GAD67 and GABAARα1 proteins in the hypothalamus of mice in L-SD group (1.39±0.19 and 1.33±0.14, respectively) were significantly higher than those in SD group and control group (P<0.05). Conclusion Leptin can up-regulate the expression of the key GABA synthase GAD67, increase the content of GABA and the expression of GABAARα1 protein in hypothalamus of sleep-deprived mice, which may be an important mechanism of leptin affecting sleep.

Association analysis of single nucleotide polymorphisms in the promoter region of GAD1 and GABRB3 with schizophrenia in Chinese Han population / 上海交通大学学报（医学版）

Objective: To investigate the correlation between the polymorphisms of locus in the promoter region of glutamate decarboxylase 1 (GAD1) gene and γ-aminobutyric acid (GABA)A receptor β-3 gene (GABRB3) and schizophrenia (SZ) in Chinese Han population. Methods: SNaPshot genotyping technique was used to detect the polymorphisms of rs3791878 and rs3749034 in the promoter region of GAD1 and rs4906902 in the promoter region of GABRB3 in 545 SZ patients (case group) and 624 healthy controls (control group). The distribution of alleles and genotypes under different genetic models between the case group and the control group in all samples were compared by SNPstats online software. The above analysis was also performed after the subjects were stratified according to gender. The correlation of G/T risk genotype of rs3791878 with the age of the first onset of male SZ was investigated by survival analysis. Results: Under over-dominant genetic model, the distribution of G/T risk genotype of rs3791878 showed statistically difference between the male SZ cases and male controls (P=0.000), and the difference was still statistically significant after Bonferroni correction (P=0.000). However, there was no significant difference in the distribution of alleles and genotypes under different genetic models of rs3749034 and rs4906902 between the case group and the control group in all samples (P>0.05), and there was also no significant difference in the distribution of alleles between the case group and the control group after them being stratified according to gender (P>0.05). Kaplan-Meier analysis showed that there was no significant difference between the age of onset of male SZ who carried G/T genotype in rs3791878 locus and that of male SZ who did not carry it (P=0.603). Conclusion: The polymorphism of rs3791878 in the promoter region of GAD1 is significantly associated with the incidence of male SZ in Chinese Han population.

Evaluation of biogenic amines producing potential of bacteria associated with proteinous food

@#Aim: The aim of this study was to assay for the biogenic amine-producing capacity of bacteria isolated from proteinous food. Methodology and results: Previously characterized bacterial isolates (Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae) obtained from proteinous food samples (smoked fish and yoghurt) were subjected to proteolytic analysis using nutrient agar supplemented with 0.2 g/mL casein and decarboxylase activity using nutrient broth supplemented with 0.004 g/mL amino acids (histidine, tyrosine, asparagines, leucine and lysine). Isolates that expressed proteolytic and decarboxylase activities were screened for biogenic amine producing capacity using decarboxylase broth which was supplemented with an amino acid (tyrosine). Biogenic amines obtained in this research were classified into primary amine and secondary amine based on their qualitative characteristics. Confirmatory and quantitative analysis of biogenic amines produced was done using high-performance liquid chromatography. The confirmatory screening revealed the presence of methylamine, ethylamine, putrescine, cadaverine, histamine, spermidine, phernylethylamine, spermine, agmatine, tyramine, dopamine, tryptamine, norepinephrine and serotonin respectively. Total biogenic amines produced by S. aureus was 70.12 mg/kg, K. pneumoniae (62.58 mg/kg) and E. coli (56.57 mg/kg) respectively. Conclusion, significance and impact of study: Enzymatic decarboxylation of free amino acids and other metabolic processes by the test organisms (S. aureus, E. coli and K. pneumoniae) leads to production of biogenic amines which can be used as a quality indicator in food in terms of degree of spoilage, use of non-hygienic raw material and poor manufacturing environment. Thus, effect of biogenic amines obtained in this research would be determined by individual toxicological threshold which can be extremely variable from few mg/kg in sensitive person to several hundred mg/kg in healthy person. The concentrations of each biogenic amine quantified are within the limit but their toxic effects depend on the type of amine, the presence of modulating compounds and the efficiency of an individual’s detoxification mechanism.