Biogenic Amine Synthesis Research Articles

In-depth genomic identification and safety evaluation of Lactobacillus Acidophilus LA85

In vitro tests assessed heat tolerance, bile salt hydrolysis, intestinal adhesion, gastrointestinal environmental tolerance, hemolysis, gelatin hydrolysis, antibiotic sensitivity, inhibition of pathogenic bacteria, and toxicity of Lactobacillus acidophilus LA85. The safety of LA85 was verified by acute oral toxicity test. Genome analysis revealed no virulence, pathogenicity, or biogenic amine synthesis genes in LA85, but one drug resistance gene. LA85 displayed strong heat tolerance, intestinal adhesion, and gastrointestinal environment tolerance, with bile salt and gelatin hydrolysis abilities, and no hemolysis. It was sensitive to European Food Safety Authority proposed antibiotics, had inhibitory effects on common pathogenic bacteria, and both its fermentation broth and cells were non-toxic. Acute oral toxicity test confirmed that LA85 (2 × 1010 CFU/kg) was safe and non-toxic in mice. The safety evaluation presented in this paper firmly establishes LA85 as a safe and effective probiotic candidate for use in a wide range of food and medical applications.

Characterization of Dnajc12 knockout mice, a model of hypodopaminergia.

Homozygous DNAJC12 c.79-2A>G (p. V27Wfs*14) loss-of-function mutations were first reported as a cause of young-onset Parkinson's disease. However, bi-allelic autosomal recessive pathogenic variants in DNAJC12 may lead to an alternative constellation of neurological features, including infantile dystonia, developmental delay, intellectual disability and neuropsychiatric disorders. DNAJC12 is understood to co-chaperone aromatic amino acid hydroxylases to foster the synthesis of biogenic amines. In vitro, we discover overexpressed DNAJC12 forms a complex with guanine triphosphate cyclohydrolase 1 (GCH1), the rate-limiting enzyme in the synthesis of tetrahydrobiopterin, a cofactor paramount for biogenic amines synthesis. We also confirm DNAJC12's interaction with tyrosine (TH) and tryptophan hydroxylase (TPH), which are rate-limiting enzymes for synthesis of biogenic amines dopamine (DA) and serotonin (5-HT). In-vitro knock-down of DNAJC12 with a siRNA destabilizes the DNAJC12-TH-GCH1 complex, reducing GCH1 levels, whereas reciprocal overexpression of both TH and GCH1 increases endogenous DNAJC12, alluding to the significance of modulating the DNAJC12-TH-GCH1 complex as a therapy for DNAJC12 and other biogenic amine disorders. We extend these investigations to a Cre-conditional knock-out mice (cDKO) in which loxP sites flanking Dnajc12 exon 2 enable its excision by cre-recombinase. With germline Cre expression, we have created a constitutive Dnajc12 knock-out (DKO). DKO mice exhibit reduced locomotion/ exploratory behavior at 3 months in automated open-field testing, accompanied by increased plasma phenylalanine which is a cardinal feature of patients with pathogenic DNAJC12 variants. In striatal tissue, total DA and 5-HT, their metabolites, and electrically-evoked DA release are all reduced. Biochemical alterations in synaptic proteins are also apparent, with enhanced phosphorylation of Th pSer31 and pSer40 reflecting biological compensation. Most immediately, cDKO and DKO mice present models to develop and refine therapeutic approaches for biogenic amines disorders, including dystonia and parkinsonism. They will also enable the pleiotropic functions of biogenic amines (including DA), usually synthesized in the brain or periphery, to be separated.

Tyramine-Mediated Hyperactivity Modulates the Dietary Habits in Helicoverpa armigera.

Helicoverpa armigera exhibits extensive variability in feeding habits and food selection. Neuronal regulation of H. armigera feeding behavior is primarily influenced by biogenic amines such as Tyramine (TA) and Octopamine (OA). The molecular responses of H. armigera to dietary challenges in the presence of TA or OA have yet to be studied. This investigation dissects the impact of OA and TA on H. armigera feeding choices and behaviors under non-host nutritional stress. It has been observed that feeding behavior remains unaltered during the exogenous administration of OA and TA through an artificial diet (AD). Ingestion of higher OA or TA concentrations leads to increased mortality. OA and TA treatment in combination with host and non-host diets results in the induction of feeding and higher locomotion toward food, particularly in the case of TA treatment. Increased expression of markers, prominin-like, and tachykinin-related peptide receptor-like transcripts further assessed increased locomotion activity. Insects subjected to a non-host diet with TA treatment exhibited increased feeding and overexpression of the feeding indicator, the Neuropeptide F receptor, and the feeding regulator, Sulfakinin, compared with other conditions. Expression of sensation and biogenic amine synthesis genesis elevated in insects fed a non-host diet in combination with OA or TA. Metabolomics analysis revealed a decreased concentration of the feeding behavior elicitor, dopamine, in insects fed a non-host diet containing TA. This work highlights the complex interplay between biogenic amine functions during dietary stress and suggests the role of tyramine in feeding promotion under stressed conditions.

Biosynthesis of Pteridines in Insects: A Review

Pteridines are important cofactors for many biological functions of all living organisms, and they were first discovered as pigments of insects, mainly in butterfly wings and the eye and body colors of insects. Most of the information on their structures and biosynthesis has been obtained from studies with the model insects Drosophila melanogaster and the silkworm Bombyx mori. This review discusses, and integrates into one metabolic pathway, the different branches which lead to the synthesis of the red pigments “drosopterins”, the yellow pigments sepiapterin and sepialumazine, the orange pigment erythropterin and its related yellow metabolites (xanthopterin and 7-methyl-xanthopterin), the colorless compounds with violet fluorescence (isoxanthopterin and isoxantholumazine), and the branch leading to tetrahydrobiopterin, the essential cofactor for the synthesis of aromatic amino acids and biogenic amines.

Inhibition of Food-Borne Pathogen Growth and Biogenic Amine Synthesis by Spice Extracts

Food-borne pathogens and their toxins cause significant health problems in humans. Formation of biogenic amines (BAs) produced by microbial decarboxylation of amino acids in food is undesirable because it can induce toxic effects in consumers. Therefore, it is crucial to investigate the effects of natural additives with high bioactivity like spice extracts to inhibit the growth of these bacteria and the formation of BAs in food. In the present study, the antibacterial effects of diethyl ether spice (sumac, cumin, black pepper, and red pepper) extracts at doses of 1% (w/v) on Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative (Klebsiella pneumoniae, Pseudomonas aeruginosa, Campylobacter jejuni, Aeromonas hydrophila, Salmonella Paratyphi A, and Yersinia enterocolitica) food-borne pathogen bacterial strains (FBP) were established. In addition, the accumulation of ammonia (AMN), trimethylamine (TMA), and biogenic amines (BAs) in tyrosine decarboxylase broth (TDB) was investigated by using high performance liquid chromatography (HPLC). Sumac extract exhibited the highest antibacterial potential against all FBPs, followed by cumin and peppers. AMN (570.71 mg/L) and TMA (53.66 mg/L) production were strongly inhibited by sumac extract in the levels of 55.10 mg/L for Y. enterocolitica and 2.76 mg/L for A. hydrophila, respectively. With the exception of S. aureus, black pepper dramatically reduced the synthesis of putrescine, serotonin, dopamine, and agmatine by FBP especially for Gram-negative ones. Furthermore, sumac extracts inhibited histamine and tyramine production by the majority of FBP. This research suggests the application of sumac extracts as natural preservatives for inhibiting the growth of FBPs and limiting the production of AMN, TMA, and BAs.

Insights into microbial communities and metabolic profiles in the traditional production of the two representative Hongqu rice wines fermented with Gutian Qu and Wuyi Qu based on single-molecule real-time sequencing

Hongqu rice wine, a famous traditional fermented alcoholic beverage, is brewed with traditional Hongqu (mainly including Gutian Qu and Wuyi Qu). This study aimed to compare the microbial communities and metabolic profiles in the traditional brewing of Hongqu rice wines fermented with Gutian Qu and Wuyi Qu. Compared with Hongqu rice wine fermented with Wuyi Qu (WY), Hongqu rice wine fermented with Gutian Qu (GT) exhibited higher levels of biogenic amines. The composition of volatile flavor components of Hongqu rice wine brewed by different fermentation starters (Gutian Qu and Wuyi Qu) was obviously different. Among them, ethyl acetate, isobutanol, 3-methylbutan-1-ol, ethyl decanoate, ethyl palmitate, ethyl oleate, nonanoic acid, 4-ethylguaiacol, 5-pentyldihydro-2(3H)-furanone, ethyl acetate, n-decanoic acid etc. were identified as the characteristic aroma-active compounds between GT and WY. Microbiome analysis based on high-throughput sequencing of full-length 16S rDNA/ITS-5.8S rDNA amplicons revealed that Lactococcus, Leuconostoc, Pseudomonas, Serratia, Enterobacter, Weissella, Saccharomyces, Monascus and Candida were the predominant microbial genera during the traditional production of GT, while Lactococcus, Lactobacillus, Leuconostoc, Enterobacter, Kozakia, Weissella, Klebsiella, Cronobacter, Saccharomyces, Millerozyma, Monascus, Talaromyces and Meyerozyma were the predominant microbial genera in the traditional fermentation of WY. Correlation analysis revealed that Lactobacillus showed significant positive correlations with most of the characteristic volatile flavor components and biogenic amines. Furthermore, bioinformatical analysis based on PICRUSt revealed that microbial enzymes related to biogenic amines synthesis were more abundant in GT than those in WY, and the enzymes responsible for the degradation of biogenic amines were less abundant in GT than those in WY. Collectively, this study provides important scientific data for enhancing the flavor quality of Hongqu rice wine, and lays a solid foundation for the healthy and sustainable development of Hongqu rice wine industry.

Tyramine mediates growth performance, immune response, and physiological regulation of Litopenaeus vannamei through dietary administration

In this study, the effects of feeding diets containing tyramine (TA) to Litopenaeus vannamei at levels of 10 (TA10), 50 (TA50), and 100 (TA100) mg/kg on growth performance, immune parameters, hemolymph glucose and lactate level, biogenic amine synthesis, and resistance against Vibrio alginolyticus were investigated. Results showed that shrimp fed with TA-containing diets had significantly higher feed efficiency and percent weight gain for a period of 56 days. The total hemocyte count increased in TA10, TA50 and TA100 after 7 and 28 days, and increased in TA100 after 14 days. The phenoloxidase activity increased in TA100 after 7 days, and respiratory bursts increased in TA100 after 7 and 14 days. In terms of resistance against V. aliginolyticus infection, the phagocytic activity increased in TA10, TA50 and TA100 after 7–28 days. The clearance efficiency increased in TA10, TA50 and TA100 after 7 and 14 days, and increased in TA 100 after 28 days. Shrimp fed with TA50 and TA100 for 28 days then challenged with V. aliginolyticus had a higher survival rate compared to those fed the basal diet at 48 h–168 h post challenges. The hemolymph glucose level was significantly decreased after being fed with TA10 at 28 days and TA100 for 56 days, while the octopamine synthesis in shrimp was improved after 14 days of being fed with TA50 and TA100, and after 28 days of being fed with TA100. These findings suggest that administering a TA diet regulated the growth performance, immune response and V. aliginolyticus resistance in L. vannamei.

Metabolism effector links in diet-induced and genetically-based obesity: A full-transcriptome study of liver tissue in experimental models in rodents

Background. When developing methods for personalized diet therapy of obesity, an urgent task is to study the molecular genetics features of the obesity pathogenesis using in vivo experimental models in laboratory animals.The aim. To determine metabolism effector links in obesity based on a comparative analysis of full-transcriptome profiles of the liver tissue of mice and rats of various strains.Materials and methods. We carried out a comparative analysis of the changes in liver transcriptome in rats and mice fed with diets of excessive energy value and exerting lipogenic effect. Data of full-transcriptome profiling using DNA microarray technology have been presented previously in 8 publications. Results. In three strains of mice treated with a high-carbohydrate high-fat diet (HCHFD), a significant differential expression (DE) of 1849 genes was revealed, of which 74 genes responded jointly in at least two groups of animals. In Wistar and Zuckerfa rats, 2109 genes responded to the consumption of HCHFD, of which 242 genes responded jointly in two groups of animals. For rodents different in genetic predisposition to the development of diet-induced obesity, the groups of genes that responded with the opposite sign of DE (depending on the genotype) in reaction to the consumption of HCHFD were identified. Bioinformatical analysis allowed establishing the presence of 43 metabolic pathways, which are targeted for the applied experimental diets exposure, in rats and 77 pathways – in mice. Four of these pathways – the pathway of retinoid metabolism, PPAR signaling pathway associated with it the previous one, xenobiotics metabolism and drugs metabolism mediated by cytochrome P450 system – responded in all groups of animals (except for female mice). The importance of the expression of Tat gene encoding tyrosine aminotransferase in the modulation of biogenic amines synthesis in diet-induced obesity was shown, which may represent a new neurometabolic regulatory function of the liver in response to the consumption of high-calorie diets. Conclusion. The analysis of the results of full-transcriptome studies showed that within each studied species (Rattus rattus and Mus domesticus) and animal sex, a number of genetic variants with a greater or lesser predisposition to the development of diet-induced obesity phenotype can be identified; and at the same time, within these variants, there is a largely similar pattern in the response of metabolism effector links to hypercaloric dietary intake. This pattern creates new prospects for translating the results of transcriptomic and metabolomic studies of laboratory animals into clinical practice in order to substantiate new approaches to personalized diet therapy of alimentary dependent diseases in patients with different genetic predisposition to obesity.

Metabolomics and Lipidomics Screening Reveal Reprogrammed Signaling Pathways toward Cancer Development in Non-Alcoholic Steatohepatitis

With the rising incidence of hepatocellular carcinoma (HCC) from non-alcoholic steatohepatitis (NASH), identifying new metabolic readouts that function in metabolic pathway perpetuation is still a demand. The study aimed to compare the metabolic signature between NASH and NASH-HCC patients to explore novel reprogrammed metabolic pathways that might modulate cancer progression in NASH patients. NASH and NASH-HCC patients were recruited and screened for metabolomics, and isotope-labeled lipidomics were targeted and profiled using the EXION-LCTM system equipped with a Triple-TOFTM 5600+ system. Results demonstrated significantly (p ≤ 0.05) higher levels of triacylglycerol, AFP, AST, and cancer antigen 19-9 in NASH-HCC than in NASH patients, while prothrombin time, platelet count, and total leukocyte count were decreased significantly (p ≤ 0.05). Serum metabolic profiling showed a panel of twenty metabolites with 10% FDR and p ≤ 0.05 in both targeted and non-targeted analysis that could segregate NASH-HCC from NASH patients. Pathway analysis revealed that the metabolites are implicated in the down-regulation of necroptosis, amino acid metabolism, and regulation of lipid metabolism by PPAR-α, biogenic amine synthesis, fatty acid metabolism, and the mTOR signaling pathway. Cholesterol metabolism, DNA repair, methylation pathway, bile acid, and salts metabolism were significantly upregulated in NASH-HCC compared to the NASH group. Metabolite-protein interactions network analysis clarified a set of well-known protein encoding genes that play crucial roles in cancer, including PEMT, IL4I1, BAAT, TAT, CDKAL1, NNMT, PNP, NOS1, and AHCYL. Taken together, reliable metabolite fingerprints are presented and illustrated in a detailed map for the most predominant reprogrammed metabolic pathways that target HCC development from NASH.

Relationship between the Dynamics of Gross Composition, Free Fatty Acids and Biogenic Amines, and Microbial Shifts during the Ripening of Raw Ewe Milk-Derived Idiazabal Cheese.

This study reports for the first time the relationship between bacterial succession, characterized by high-throughput sequencing (sequencing of V3-V4 16S rRNA regions), and the evolution of gross composition, free fatty acids (FFAs) and biogenic amines (BAs) during cheese ripening. Specifically, Idiazabal PDO cheese, a raw ewe milk-derived semi-hard o hard cheese, was analysed. Altogether, 8 gross parameters were monitored (pH, dry matter, protein, fat, Ca, Mg, P and NaCl) and 21 FFAs and 8 BAs were detected. The ripening time influenced the concentration of most physico-chemical parameters, whereas the producer mainly affected the gross composition and FFAs. Through an O2PLS approach, the non-starter lactic acid bacteria Lactobacillus, Enterococcus and Streptococcus were reported as positively related to the evolution of gross composition and FFAs release, while only Lactobacillus was positively related to BAs production. Several environmental or non-desirable bacteria showed negative correlations, which could indicate the negative impact of gross composition on their growth, the antimicrobial effect of FFAs and/or the metabolic use of FFAs by these genera, and their ability to degrade BAs. Nonetheless, Obesumbacterium and Chromohalobacter were positively associated with the synthesis of FFAs and BAs, respectively. This research work provides novel information that may contribute to the understanding of possible functional relationships between bacterial communities and the evolution of several cheese quality and safety parameters.

Assessment of the safety and probiotic properties of Roseburia intestinalis: A potential "Next Generation Probiotic".

Roseburia intestinalis is an anaerobic bacterium that produces butyric acid and belongs to the phylum Firmicutes. There is increasing evidence that this bacterium has positive effects on several diseases, including inflammatory bowel disease, atherosclerosis, alcoholic fatty liver, colorectal cancer, and metabolic syndrome, making it a potential “Next Generation Probiotic.” We investigated the genomic characteristics, probiotic properties, cytotoxicity, oral toxicity, colonization characteristics of the bacterium, and its effect on the gut microbiota. The genome contains few genes encoding virulence factors, three clustered regularly interspaced short palindromic repeat (CRISPR) sequences, two Cas genes, no toxic biogenic amine synthesis genes, and several essential amino acid and vitamin synthesis genes. Seven prophages and 41 genomic islands were predicted. In addition to a bacteriocin (Zoocin A), the bacterium encodes four metabolic gene clusters that synthesize short-chain fatty acids and 222 carbohydrate-active enzyme modules. This bacterium is sensitive to antibiotics specified by the European Food Safety Authority, does not exhibit hemolytic or gelatinase activity, and exhibits some acid resistance. R. intestinalis adheres to intestinal epithelial cells and inhibits the invasion of certain pathogens. In vitro experiments showed that the bacterium was not cytotoxic. R. intestinalis did not affect the diversity or abundance of the gut flora. Using the fluorescent labelling method, we discovered that R. intestinalis colonizes the cecum and mucus of the colon. An oral toxicity study did not reveal any obvious adverse effects. The lethal dose (LD)50 of R. intestinalis exceeded 1.9 × 109 colony forming units (CFU)/kg, whereas the no observed adverse effect level (NOAEL) derived from this study was 1.32 × 109 CFU/kg/day for 28 days. The current research shows that, R. intestinalis is a suitable next-generation probiotic considering its probiotic properties and safety.

Long-term neurological and psychiatric outcomes in patients with aromatic l-amino acid decarboxylase deficiency

Introductionl-amino acid decarboxylase deficiency (AADCD) is an ultrarare autosomal recessive defect of biogenic amine synthesis that presents with early-onset encephalopathy progressing to severe neurological impairment and intellectual disability. We aimed to explore neurocognitive and behavioral profiles associated with AADCD and possible factors predicting outcome in more detail. MethodsNine AADCD patients (23.2 ± 10.3 years; range 8–40) underwent systematic clinical and neuropsychological assessment. Diagnostic levels of CSF 5-hydroxyindolacetic acid (5-HIAA) and homovanillic acid (HVA), and DDC genotype (as ascertained by American College of Medical Genetics and Genomics grading) were included in the data analysis. ResultsAll AADCD patients were affected by intellectual disability and psychiatric disorders. Movement disorders included parkinsonism-dystonia, dysarthria, and oculogyric crises. CSF 5-HIAA and HVA levels at diagnosis had a significant influence on adaptive behavior and executive function performance. Patients homozygous for DDC pathogenetic variants showed lower CSF 5-HIAA and HVA levels and higher Unified Parkinson's Disease Rating Scale scores. The disease showed a self-limiting clinical course with partial improvement under pharmacological treatment (B6 and dopamine mimetic drugs). ConclusionsPatients with AADCD suffer from neuropsychological and psychopathological impairment, which may be improved but not reversed under the present therapeutic approach. However, cognitive functioning should be specifically examined in order to avoid its underestimation on the basis of movement disorder severity. Genotype and biogenic amine level at diagnosis have an important prognostic value.

Synthesis of Biogenic Amines by Lactic Acid Bacteria on Media of Plant and Animal Origin

Synthesis of Biogenic Amines by Lactic Acid Bacteria on Media of Plant and Animal Origin

Safety Assessment of Lactiplantibacillus plantarum TWK10 Based on Whole-Genome Sequencing, Phenotypic, and Oral Toxicity Analysis.

Lactiplantibacillus plantarum TWK10 (TWK10), isolated from Taiwanese pickled cabbage, has been demonstrated to exert beneficial probiotic effects in both mice and humans. Here, we comprehensively assessed the safety of TWK10 using both in vivo and in vitro approaches, including whole-genome sequence analysis, an assessment of hemolytic activity, and performing an antimicrobial susceptibility test, the Ames bacterial reverse mutation assay, the chromosomal aberration test, a rodent peripheral blood micronucleus test, and the 28-day subacute oral toxicity assay. The results showed that there was no significant increase in the incidence of reverse mutations or chromosomal aberrations following exposure to TWK10. Moreover, no significant changes were detected either in the number of reticulocytes or the incidence of micronuclei in ICR mice, and no subacute toxicity was recorded in SD rats at the oral TWK10 dosage of 2000 mg/kg body weight/day repeated for 28 days. Additionally, TWK10 exhibited no hemolytic activity and was susceptible to all the antibiotics tested, except kanamycin. However, no antimicrobial resistance genes, virulence factors, or genes involved in biogenic amine synthesis were found in the genome of TWK10. Our findings demonstrated that TWK10 has high potential of being safe for human consumption as a probiotic.

Mechanism of biogenic amine synthesis of Enterococcus faecium isolated from Sanchun ham.

Sanchuan ham, produced in Yunnan, China, is food with ethnic characteristics favored by consumers. However, it can contain biogenic amines such as tyramine that are harmful to health, and the synthesis mechanism of biogenic amines in Sanchuan ham is not clear. This study focuses on the regulation of biogenic amine synthesis by quorum sensing. We used high‐performance liquid chromatography to detect the content of biogenic amine in different kinds of ham and found that the content of biogenic amine in Sanchuan ham was higher than that in others. Tyramine‐producing strain isolated from Sanchuan ham was identified as Enterococcus faecium. By monitoring the growth and tyramine synthesis of Enterococcus faecium under cultured conditions, the results found that high temperature and low salt increased tyramine production by E. faecium. After seven exogenous amino acids were applied to E. faecium, only tyrosine could promote the production of tyramine in E. faecium, and tyramine could not be synthesized in E. faecium until a certain amount was reached, indicating the presence of microbial quorum sensing signal molecules in the synthesis of tyramine in E. faecium. Untargeted metabolomics analysis of the differential metabolites produced by E. faecium showed that the contents of some peptides, especially alanyl‐leucine, were significantly increased. Further experiments with synthetic alanyl‐leucine illustrated that alanyl‐leucine activated the expression of tyrosine decarboxylase (tyrDC), thereby regulating the synthesis of tyramine by E. faecium. Alanyl‐leucine acted as quorum sensing signal molecules for biogenic amine synthesis by E. faecium, which provided a theoretical basis for reducing biogenic amine accumulation in ham. It is beneficial to control the content of biogenic amines in ham in the future.

Lactobacillus curvatus from fermented sausages as new probiotic functional foods

This research examined in vitro probiotic potential of Lactobacillus curvatus isolates from fermented sausage originating in Southeast Serbia which was prepared using traditional production techniques. Strains of L. curvatus were isolated and identified at the level of species using API 50CHL sets and 16s rDNA sequencing, after which their probiotic potential was measured. The research consisted of the examination of isolate survival rates in the gastrointestinal tract, synthesis of biogenic amines, the growth on the media with different quantities of phenol, antibiotic resistance test, and antimicrobial activity against clinical strains of Pseudomonas spp., Proteus spp., Enterobacter spp., Escherichia coli and Listeria monocytogenes. The examined isolates have shown a good survival rate at low pH in the simulated stomach and small intestine conditions. Synthesis of biogenic amines was exhibited by the isolate sk1-10, which had a positive reaction to histidine. Analyzed isolates grew well on media with 0.1% and 0.2% of phenol, L.curvatus sk1-8 and sk5-2 have grown in media with 0.3% phenol. All tested isolates have exhibited high sensitivity to most analyzed antibiotics (tetracycline, amoxicillin, ceftriaxone, erythromycin, penicillin), resistance to ofloxacin, and cephalexin isolates sk4-3a and sk4-15. The examined isolates have shown a broad inhibitory spectrum against pathogens.

EXPRESSION AND ACTIVITY OF AMINOTRANSFERASES IN THE LIVER OF STREPTOZOTOCIN-DIABETIC RATS: THE EFFECT OF MIFEPRISTONE.

Interventions that suppress hepatic gluconeogenesis from amino acids may be useful for improving glycemic control in diabetic patients. It was shown that administration of glucocorticoid receptor antagonist Mifepristone (MIF) leads to variously pronounced changes in the alanine-, aspartate-, tyrosine- aminotransferases (ALT, AST, TAT) activity in the liver of experimental animals. It has been suggested that this selective effect of MIF may be related to differences in the expression of the corresponding genes. The aim of the study was to investigate the gene expression and activity of ALT, AST and TAT in the liver of rats with streptozotocin-related diabetes (StD) under the long-term oral MIF administration. Male Wistar rats (n=48) with StD under the 10-days oral MIF administration were used. It was measured the activity of ALT, AST, TAT enzymes and relative expression of this genes in the liver of experimental animals. In rats with StD the gene expression of all three studied aminotransferases in the liver was statistically significantly increased and their activity was increased as well. MIF administration did not change the studied genes expression and enzymes activity to healthy rats and caused a decrease in expression of ALT and AST genes and activity of these enzymes to rats with StD. However, the expression of the TAT gene and the activity of this enzyme in the liver of rats with StD increased upon MIF administration in comparison with animals with StD. The introduction of MIF against the background of StD reduces the expression of genes and the activity of ALT and AST in the liver, what determine the transamination of amino acids to include them in gluconeogenesis, but increases the expression of genes and the activity of TAT, what determine the inclusion of tyrosine in the biogenic amines synthesis. The mechanisms of such selectivity require further study.

Cloning and characterization of a key enzyme in octopaminergic pathway: Tyramine beta-hydroxylase from Litopenaeus vannamei, as expressed during Vibrio alginolytics infection and hypothermal stress

Tyramine beta-hydroxylase (TBH) is needed for the biosynthesis of the octopamine (OA) from tyramine (TA). Both OA and TA act as neurotransmitters, neurohormones, and neuromodulators in the invertebrate nervous system. In this study, TBH was identified in white shrimp, Litopenaeus vannamei, and further investigation on its potential function was conducted after inducing hypothermal stress and Vibrio alginolyticus infection. TBH of L. vannamei (LvTBH) was comprised 2178 nucleotide residues and contained an open reading frame encoding 408 amino acids, belonging to the Copper type II, ascorbate-dependent monooxygenases, was characterized by two Cu2_monooxygen domains and five glycosylation sites. LvTBH expression was especially abundant in muscle, and mainly in brain and thoracic ganglia of nervous system, eyestalk tissues, epithelium, and stomach, as determined by quantitative real-time PCR. The effects of hypothermal stress showed significant increases in LvTBH at 15, 30 and 60 min in brain and at 30 min in haemocyte, accompanied by an increase in OA level in haemolymph from 15 to 60 min. Significant increases in LvTBH occurred at 15, 30 and 60 min in haemocyte and at 60 min in brain tissue, and was proportional to the OA level of haemolymph under Vibrio alginolyticus infection from 30 to 60 min. Here, we demonstrated that LvTBH is functionally responsible for biogenic amine synthesis, suggesting that the increased release of OA in haemolymph for potential modulation of physiological and immunological responses is the consequence of the upregulated LvTBH gene expression in L. vannamei exposed to hypothermal stress and Vibrio alginolyticus infection.

Secondary biogenic amine deficiencies: genetic etiology, therapeutic interventions, and clinical effects.

Monoamine neurotransmitter disorders present predominantly with neurologic features, including dystonic or dyskinetic cerebral palsy and movement disorders. Genetic conditions that lead to secondary defects in the synthesis, catabolism, transport, and metabolism of biogenic amines can lead to neurotransmitter abnormalities, which can present with similar features. Eleven patients with secondary neurotransmitter abnormalities were enrolled between 2011 and 2015. All patients underwent research-based whole exome and/or whole genome sequencing (WES/WGS). A trial of treatment with levodopa/carbidopa and 5-hydroxytryptophan was initiated. In six families with abnormal neurotransmitter profiles and neurological phenotypes, variants in known disease-causing genes (KCNJ6, SCN2A, CSTB in 2 siblings, NRNX1, KIF1A and PAK3) were identified, while one patient had a variant of uncertain significance in a candidate gene (DLG4) that may explain her phenotype. In 3 patients, no compelling candidate genes were identified. A trial of neurotransmitter replacement therapy led to improvement in motor and behavioral symptoms in all but two patients. The patient with KCNJ6 variant did not respond to L-dopa therapy, but rather experienced increased dyskinetic movements even at low dose of medication. The patient's symptoms harboring the NRNX1 deletion remained unaltered. This study demonstrates the utility of genome-wide sequencing in further understanding the etiology and pathophysiology of neurometabolic conditions, and the potential of secondary neurotransmitter deficiencies to serve as novel therapeutic targets. As there was a largely favorable response to therapy in our case series, a careful trial of neurotransmitter replacement therapy should be considered in patients with cerebrospinal fluid (CSF) monoamines below reference range.

Cloning and characterization of tyrosine decarboxylase (TDC) from Litopenaeus vannamei, and its roles in biogenic amines synthesis, immune regulation, and resistance to Vibrio alginolyticus by RNA interference

The biogenic amines, tyramine and octopamine, in the octopaminergic synthesis pathway play critical roles in regulating physiological and immunological homeostasis in Litopenaeus vannamei. Tyrosine decarboxylase (TDC) is an enzyme catalyzing the first decarboxylation step in the biosynthesis of tyramine and octopamine. The full-length gene sequence of TDC cloned from the brain of L. vannamei (LvTDC) was predicted to encode a 779-amino acid protein with a pyridoxal-dependent decarboxylase-conserved domain in close phylogenetic relationship with arthropod TDCs. LvTDC gene expression was found to be abundant in nervous thoracic ganglia. RNA interference was used to assess the immune and physiological function of LvTDC. The LvTDC knockdown shrimp revealed significant decreases in the total haemocyte count, hyaline cells, antimicrobial peptides, respiratory bursts, gene expression, respiratory bursts of haemocytes per unit of haemolymph, and phagocytic activity and clearance efficiency toward Vibrio alginolyticus. Furthermore, LvTDC knockdown was accompanied by decreases in octopamine deficiency. In the V. alginolyticus challenge test, the survival rate of LvTDC knockdown shrimp was lower than the shrimp injected with DEPC-water or GAPDH-dsRNA. In conclusion, the cloned LvTDC was responsible for octopaminergic synthesis, which then regulated physiological and immune responses in L. vannamei.