Uridine Monophosphate Research Articles

Leaf Bacteriome in Sugar Beet Shows Differential Response against Beet curly top virus during Resistant and Susceptible Interactions

Beet curly top virus (BCTV) significantly reduces sugar beet yield in semi-arid production areas. Genetic resistance to BCTV is limited; therefore, identification of additional resistance-associated factors is highly desired. Using 16S rRNA sequencing and BCTV resistant (R) genotypes (KDH13, KDH4-9) along with a susceptible (S) genotype (KDH19-17), we investigated leaf bacteriome changes during BCTV post inoculation (pi). At day 6 (~6-week-old plants), Cyanobacteria were predominant (~90%); whereas, at week 4 (~10-week-old plants) Firmicutes (11–66%), Bacteroidetes (17–26%), and Verrucomicrobia (12–29%) were predominant phyla and genotype dependent. Both Bacteroidetes and Verrucomicrobia, increased post infection only in the R lines. The bacterial genera Brevibacillus increased at 6 dpi, and Akkermansia and Bacteroides at 4 wkpi in the R lines. Linear discriminant analysis effect size (LEfSe) identified potential biomarkers in the R vs. S lines. Functional profiling revealed bacterial enrichment associated with the TCA cycle, polyisoprenoid, and L-methionine biosynthesis pathways only in KDH4-9 at 6 dpi. At 4 wkpi, bacteria associated with tryptophan and palmitate biosynthesis in the R lines, and uridine monophosphate, phosphatidyl glycerol, and phospholipid biosynthesis in the S line, were enriched. Future characterization of bacterial genera with antiviral properties will help establish their use as biocontrol agents/biomarkers against BCTV.

Uricase sensitizes hepatocellular carcinoma cells to 5-fluorouracil through uricase-uric acid-UMP synthase axis.

Conventional chemotherapy plays a key role in hepatocellular carcinoma (HCC) treatment, however, with intrinsic or acquired chemoresistance being a major constraint. Here, we aimed to identify potential target to reverse such chemoresistance. In the present study, we found significant difference in uridine monophosphate synthetase (UMPS) expression between 5-FU resistant and sensitive HCC cell lines and the overexpression or downregulation of UMPS impacted 5-FU response in HCC cells. We further found that inhibition of UMPS activity with uric acid at concentration present in human plasma decreased the 5-FU sensitivity of HCC cells, while reduction of uric acid levels with uricase improved the 5-FU sensitivity of HCC cells as well as colorectal cancer cells. In vivo studies also suggested that modulation of uric acid levels did affect 5-FU sensitivity of tumors. These data indicated that UMPS was correlated with the 5-FU resistance in HCC cells and uricase sensitized cancer cells to 5-FU through uricase-uric acid-UMP synthase axis, which provided a potential strategy to improve the efficacy of 5-FU-based chemotherapy for human cancers.

Differential Effects of mTORC1 and mTORC2 Inhibition on High-Resolution Mass Spectrometry (HRMS) Metabolomics and the Internal Exposome in Pancreatic Beta Cell Lines

ObjectivesThe mechanistic Target of Rapamycin Complexes (mTORC1/mTORC2) are critical nodes for metabolism. We applied an HRMS-based untargeted metabolomics approach to determine the role of mTORC1/mTORC2 on the internal exposome in pancreatic cell line (β-TC6). mTORC1 is a nutrient-sensing network, while mTORC2 phosphorylates Akt on Ser473 and modulates energy metabolism, thus mTORC1/mTORC2 are targets for precision nutrition.MethodsWe used glucose-responsive, insulin-secreting, pancreatic beta-cell lines. mTORC1/mTORC2 were inhibited by RapaLink-1, a third-generation inhibitor encompassing rapamycin linked to an mTOR kinase inhibitor, or rapamycin, compared to the control. We compared the HRMS-based untargeted metabolomics (LC-MS/MS) between groups to identify the differentially expressed metabolites, predictive metabolic networks, and systems biology pathways. We employed the XCMS online cloud-based bioinformatics platform to link mTOR-regulated metabolites to biological pathways using the python mummichog algorithm. Statistical significance (P < 0.001) was assessed by ANOVA followed by adhoc unpaired t-test.ResultsPCA dimension reduction and cloud plot clustering machine learning showed differential expression of metabolites between RapaLink and rapamycin-treated pancreatic beta cells. RapaLink significantly increased aminobutyrate (P < 0.001), D-glucose (p = 0.02), and O-phosphoryl ethanolamine (p = 0.003), compared to rapamycin. RapaLink also decreased glycine level (P < 0.000001) compared to the control. While both RapaLink and rapamycin decreased alanine (p = 0.003), L-asparagine (p = 0.01), L- aspartate (p < 0.001), taurine (p = 0.003), and uridine monophosphate (p = 0.004) compared to the control. The predictive metabolic pathways affected included malate-aspartate shuttle, adenosine nucleotide degradation, and glucose degradation.ConclusionsmTORC1 and mTORC2 have differential effects on glucose, bile acids, short-chain fatty acids, nucleotides, and amino acid metabolism, and thus could serve as targets for precision nutrition in pancreatic diseases and type 2 diabetes interventions.Funding SourcesFunded by the City University of New York, GC Advanced Science Research Center Seed Grant Award # 95,649–00. XCMS online is a cloud-based open-source bioinformatics platform developed by the Scripps Institute.

Effects of Different Chemicals on Sexual Regulation in Persimmon (Diospyros kaki Thunb.) Flowers

Research on crop sexuality is important for establishing systems for germplasm innovation and cultivating improved varieties. In this study, androecious persimmon trees were treated with various concentrations of ethrel (100, 500, and 1,000 mg/L) and zeatin (1, 5, and 10 mg/L) to investigate the morphological, physiological, and molecular characteristics of persimmon. Ethrel at 1,000 mg/L and zeatin at 10 mg/L both significantly reduced the stamen length and pollen grain diameter in androecious trees. Ethrel treatment also led to reduced stamen development with degenerated cellular contents; zeatin treatment promoted the development of arrested pistils via maintaining relatively normal mitochondrial morphology. Both treatments altered carbohydrate, amino acid, and endogenous phytohormone contents, as well as genes associated with hormone production and floral organ development. Thereafter, we explored the combined effects of four chemicals, including ethrel and zeatin, as well as zebularine and 5-azacytidine, both of which are DNA methylation inhibitors, on androecious persimmon flower development. Morphological comparisons showed that stamen length, pollen viability, and pollen grain diameter were significantly inhibited after combined treatment. Large numbers of genes involving in carbohydrate metabolic, mitogen-activated protein kinase (MAPK) signaling, and ribosome pathways, and metabolites including uridine monophosphate (UMP) and cyclamic acid were identified in response to the treatment, indicating complex regulatory mechanisms. An association analysis of transcriptomic and metabolomic data indicated that ribosomal genes have distinct effects on UMP and cyclamic acid metabolites, explaining how male floral buds of androecious persimmon trees respond to these exogenous chemicals. These findings extend the knowledge concerning sexual differentiation in persimmon; they also provide a theoretical basis for molecular breeding, high-yield cultivation, and quality improvement in persimmon.

The Metabolic and Non-Metabolic Roles of UCK2 in Tumor Progression.

Enhanced nucleoside metabolism is one of the hallmarks of cancer. Uridine-cytidine kinase 2 (UCK2) is a rate-limiting enzyme of the pyrimidine salvage synthesis pathway to phosphorylate uridine and cytidine to uridine monophosphate (UMP) and cytidine monophosphate (CMP), respectively. Recent studies have shown that UCK2 is overexpressed in many types of solid and hematopoietic cancers, closely associates with poor prognosis, and promotes cell proliferation and migration in lung cancer and HCCs. Although UCK2 is thought to catalyze sufficient nucleotide building blocks to support the rapid proliferation of tumor cells, we and other groups have recently demonstrated that UCK2 may play a tumor-promoting role in a catalytic independent manner by activating oncogenic signaling pathways, such as STAT3 and EGFR-AKT. By harnessing the catalytic activity of UCK2, several cytotoxic ribonucleoside analogs, such as TAS-106 and RX-3117, have been developed for UCK2-mediated cancer chemotherapy. Moreover, we have demonstrated that the concurrent targeting of the catalytic dependent and independent features of UCK2 could synergistically inhibit tumor growth. These findings suggest that UCK2 may serve as a potential therapeutic target for cancer treatment. In this mini-review, we introduced the genomic localization and protein structure of UCK2, described the role of UCK2 in tumor development, discussed the application of UCK2 in anti-tumor treatment, and proposed concurrent targeting of the catalytic and non-catalytic roles of UCK2 as a potential therapeutic strategy for cancer treatment.

Effectiveness of nutritional interventions to prevent nonprogressive congenital and perinatal brain injuries: a systematic review and meta-analysis of randomized trials.

Nutritional interventions for newborns with brain injury are scarce, and there are gaps in the knowledge of their mechanisms of action in preventing the occurrence of cerebral palsy (CP) or the incidence of other developmental disabilities. The objective of this review was to assess the effect of nutritional interventions in preventing nonprogressive congenital or perinatal brain injuries, or in improving outcomes related to neurological development. Randomized trials on any nutritional intervention for pregnant women at risk of preterm delivery, or for children with low birth weight, preterm, or with confirmed or suspected microcephaly, CP, or fetal alcohol syndrome disorders (FASDs) were retrieved from MEDLINE, Embase, Scopus, Web of Science, LILACS, and CENTRAL databases from inception to September 17, 2020. Data extraction, risk of bias (Cochrane Risk of Bias tool 2), and quality of evidence (GRADE approach) were assessed by 2 authors. Pooled risk ratios (RRs) with 95% confidence intervals were calculated using a random-effects meta-analysis. Seventeen studies were included on intravenous interventions (magnesium sulfate [n = 5], amino acids [n = 4], vitamin A [n = 1], and N-acetylcysteine [n = 1]); enteral interventions (vitamin D [n = 1], prebiotic [n = 1], nutrient-enriched formula [n = 1], and speed of increasing milk feeds [n = 1]); and oral interventions (choline [n = 1] and docosahexaenoic acid, choline, and uridine monophosphate [n = 1]). All studies assessed CP, except 1 on FASDs. Eight studies were judged as having high risk of bias. Five studies (7413 babies) with high-quality evidence demonstrated decreased risk of childhood CP (RR = 0.68, 95% CI: 0.52-0.88) with magnesium sulfate. Interventions with amino acids had no effect on CP prevention or other outcomes. Except for 1 study, no other intervention decreased the risk of CP or FASDs. Although different types of nutritional interventions were found, only those with antenatal magnesium sulfate were effective in decreasing CP risk in preterm infants. Well-designed, adequately powered randomized clinical trials are required.

D-Methionine and 2-hydroxy-4-methylthiobutanoic acid i alter beta-casein, proteins and metabolites linked in milk protein synthesis in bovine mammary epithelial cells.

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco’s modified Eagle’s medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose–galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.

Computational Study on the Electrostatic Interactions between Uracil‐DNA Glycosylase (UDG) and DNA

In DNA repair mechanism, Uracil‐DNA glycosylase (UDG) is one of the most important enzymes that are involved in the process of base excision repair (BER), the function of UDG is to repair the uracil‐induced DNA lesion by removing uracil from damaged DNA. Uracil in DNA may occur due to the cytosine deamination or deoxy uridine monophosphate (dUMP) residues misincorporation during DNA synthesis. Medical evidences haven shown that an abnormal expression of UDG is related to different types of cancer, including colorectal cancer, lung cancer, liver cancer, etc. Therefore, the research of UDG is crucial in cancer treatment and prevention, as well as other clinical activities. Here we applied multiple computational methods to study the UDG in several perspectives: Understand the stability of UDG enzyme in different pH conditions; study the differences in charge distribution between the pocket side and non‐pocket side of UDG; analyze the field line distribution at the interfacial area between UDG and DNA; perform electrostatic binding forces analyses of special region of UDG (pocket area) and target DNA base (uracil); as well as investigate the charged residues on UDG binding pocket and binding interface. Our results show that it is the whole UDG binding interface rather than the UDG binding pocket area alone who provides the binding attractive force to a damaged DNA at uracil base.

Excess-electron attachment and ionization of aqueous uridine monophosphate anion

We applied quantum mechanics/classical mechanics simulations to study excess-electron attachment and ionization of uridine monophosphate anion (dUMP−) in explicit aqueous solutions. We calculated vertical electron affinities (VEAs), adiabatic electron affinities (AEAs), vertical detachment energies (VDEs), vertical ionization energies (VIEs), and adiabatic ionization energies (AIEs) of the 40 structures obtained from molecular dynamic trajectory. The excess-electron and hole distributions were analyzed in electron attachment and ionization of aqueous dUMP−. The converged mean VEA (−0.31 eV) and AEA (2.13 eV) suggest that excess-electron can easily attach to dUMP−. The mean vertical (−0.50 e) and adiabatic (−0.62 e) excess-electron on uracil reveal that main excess-electrons are localized on nucleobases at the most snapshots. The distributions at several special snapshots demonstrate the excess-electron delocalization over nucleobases/ribose or ribose/phosphate group after the structural relaxations of dUMP2− dianion. The VDE value (2.78 eV) indicates that dUMP2− dianion could be very stable. Moreover, the mean VIE is 8.13 eV which is in agreement with the previous calculation using solvation model. The hole distributions on uracil suggest that the nucleobases are easily ionized after the irradiation of high-energy rays. In vertical ionizations, the holes would be delocalized over uracil and ribose at several snapshots. Observing the adiabatic hole distributions, it can be found that electrons on phosphate group and holes on nucleobases can be transferred to ribose at the special snapshots in the structural relaxation of neutral species.

Profile of Nucleotides in Chinese Mature Breast Milk from Six Regions.

This study measured the total potentially available nucleoside (TPAN) content in breast milk from six different regions of China as a part of the Maternal Nutrition and Infant Investigation (MUAI) study. A total of 631 breast milk samples were collected from healthy, lactating women with singleton, full-term pregnancies between 40 and 45 days postpartum in Changchun, Chengdu, Lanzhou, Shanghai, Tianjin, and Guangzhou. TPAN and free 5′-monophosphate nucleotide (5′-MNT) contents were determined by high-performance liquid chromatography. The TPAN content of the Chinese mature milk ranged from 11.61 mg/L to 111.09 mg/L, with a median level of 43.26 mg/L. Four types of nucleotides were identified, and the median levels of cytidine monophosphate (CMP), uridine monophosphate (UMP), guanosine monophosphate (GMP), and adenosine monophosphate (AMP) were 22.84 mg/L, 9.37 mg/L, 4.86 mg/L, and 4.80 mg/L, respectively. CMP was the predominant nucleotide, accounting for 52.9% of the TPAN content, while free 5′-MNT accounted for 18.38% of the TPAN content. The distribution pattern of the TPAN content and level of the individual nucleotides were significantly different among the selected regions (p < 0.05), but the result showed no significant differences in the TPAN level in breast milk (p > 0.05). In addition, no correlation was reported between the geographic distribution and TPAN levels. This result showed that TPAN better reflects the level of total potential nucleosides in Chinese breast milk rather than 5′-MNT in free form. CMP, UMP, GMP, and AMP are the only 4 types of nucleotides reported in all detections. In addition, results revealed a large variation of TPAN levels in Chinese breast milk across six regions, so that the median value may not be the optimal fortification level of TPAN for Chinese infant populations.

Structural basis for the allosteric inhibition of UMP kinase from Gram-positive bacteria, a promising antibacterial target.

Tuberculosis claims significantly more than one million lives each year. A feasible way to face the issue of drug resistance is the development of new antibiotics. Bacterial uridine 5'-monophosphate (UMP) kinase is a promising target for novel antibiotic discovery as it is essential for bacterial survival and has no counterpart in human cells. The UMP kinase from M. tuberculosis is also a model of particular interest for allosteric regulation with two effectors, GTP (positive) and UTP (negative). In this study, using X-ray crystallography and cryo-electron microscopy, we report for the first time a detailed description of the negative effector UTP-binding site of a typical Gram-positive behaving UMP kinase. Comparison between this snapshot of low affinity for Mg-ATP with our previous 3D-structure of the GTP-bound complex of high affinity for Mg-ATP led to a better understanding of the cooperative mechanism and the allosteric regulation of UMP kinase. Thermal shift assay and circular dichroism experiments corroborate our model of an inhibition by UTP linked to higher flexibility of the Mg-ATP-binding domain. These new structural insights provide valuable knowledge for future drug discovery strategies targeting bacterial UMP kinases.

Nutritional value of black soldier fly (Hermetia illucens) larvae processed by different methods.

Nutritional value of black soldier fly (Hermetia illucens) larvae (BSFL) processed by three different methods of treatment was compared. The resulting products were the spray-dried BSFL (SPR), oven-dried BSFL 1 (OVN1) and oven-dried BSFL 2 (OVN2). Proximate chemical composition, and profiles of amino acids, fatty acids, minerals, heavy metals, vitamins and nucleotides were analysed and compared. The tested BSFL meals were considered to have a good profile of essential amino acids (EAAs), with leucine, lysine, valine, and histidine being the dominant EAAs. Their content of saturated fatty acids exceeded that of the unsaturated fatty acids. Vitamins B1, B2, and C were also present in the samples. Minerals such as calcium, potassium, phosphorus, sodium, magnesium, zinc, iron, manganese and copper were found to be in adequate amounts in almost all the samples. Heavy metals in the BSFL meals were mostly below 1g kg-1. Nucleotides such as inosine monophosphate and uridine monophosphate occurred in all the BSFL meals. Other nucleotides, including guanosine monophosphate, adenosine monophosphate, xanthosine monophosphate, and cytidine monophosphate were detected in either or both of SPR and OVN2. In general, the nutritional value of the BSFL meals tested in the present study was influenced by the method of processing.

Effective and repeatable chromatographic separation of 5 nucleotides in infant formula milk powder by ion-pair high-performance liquid chromatography–ultraviolet

A robust method using HPLC-UV was developed to improve the accuracy and repeatability of a quantitative method to detect 5 nucleotides (cytidine-monophosphate, uridine monophosphate, adenosine monophosphate, guanine monophosphate, and inosine monophosphate) in infant formulas. The results showed that efficient separation could not be achieved without strict conditions. The proposed method displayed a strong linear relationship (R2 > 0.9999) of single nucleotide in infant formula milk powder in the range of 10 to 1,000 mg/kg, a steady recovery (80.0% ∼110.0%) with relative standard deviation from 0.5% to 3.5%, under strict conditions of hydrophilic C18 column with di-isopropyl at 62.5 ± 2.5°C (± standard deviation), 0.65 ± 0.1 mg/mL tetrabutylammonium bisulfate, and mobile phase of pH of 2.75 ± 0.02. By applying this method on a series of milk products in the Chinese market, we found a few of them exceeded the legal limits of nucleotides.

Aqueous-Microdroplet-Driven Abiotic Synthesis of Ribonucleotides.

Phosphorylation for ribonucleotide formation is a critical step in the origin of life but has had limited success due to the thermodynamic and kinetic constraints in aqueous media. Here, we report that the production of ribonucleotides from ribonucleosides in the presence of monopotassium phosphate (KH2PO4) spontaneously proceeded in aqueous microdroplets under ambient conditions and without using a catalyst. A full set of ribonucleotides including adenosine monophosphate (AMP), guanosine monophosphate (GMP), uridine monophosphate (UMP), and cytidine monophosphate (CMP) were generated on the scale of a few milliseconds. The aqueous microdroplets could transfer the ribonucleotides to oligoribonucleotides and showed mutual compatibility for individual phosphorylation. Conditions established the dependence of the conversion ratio on the droplet size and suggested that the condensation reactions occurred at or near the microdroplets' surface. This aqueous microdroplet approach also provides a route for elucidating phosphorylation chemistry in the prebiotic era.

Palladium-catalyzed C-H olefination of uridine, deoxyuridine, uridine monophosphate and uridine analogues.

The palladium-catalyzed oxidative C–H olefinations of uridine, deoxyuridine, uridine monophosphate and uridine analogues are reported herein. This protocol provides an efficient, atom-economic and environmentally friendly approach to the synthesis of biologically important C5-alkene modified uracil/uridine-containing derivatives and pharmaceutical candidates.

Nutritional Supplementation Reduces Lesion Size and Neuroinflammation in a Sex-Dependent Manner in a Mouse Model of Perinatal Hypoxic-Ischemic Brain Injury.

Perinatal hypoxia-ischemia (HI) is a major cause of neonatal brain injury, leading to long-term neurological impairments. Medical nutrition can be rapidly implemented in the clinic, making it a viable intervention to improve neurodevelopment after injury. The omega-3 (n-3) fatty acids docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3), uridine monophosphate (UMP) and choline have previously been shown in rodents to synergistically enhance brain phospholipids, synaptic components and cognitive performance. The objective of this study was to test the efficacy of an experimental diet containing DHA, EPA, UMP, choline, iodide, zinc, and vitamin B12 in a mouse model of perinatal HI. Male and female C57Bl/6 mice received the experimental diet or an isocaloric control diet from birth. Hypoxic ischemic encephalopathy was induced on postnatal day 9 by ligation of the right common carotid artery and systemic hypoxia. To assess the effects of the experimental diet on long-term motor and cognitive outcome, mice were subjected to a behavioral test battery. Lesion size, neuroinflammation, brain fatty acids and phospholipids were analyzed at 15 weeks after HI. The experimental diet reduced lesion size and neuroinflammation specifically in males. In both sexes, brain n-3 fatty acids were increased after receiving the experimental diet. The experimental diet also improved novel object recognition, but no significant effects on motor performance were observed. Current data indicates that early life nutritional supplementation with a combination of DHA, EPA, UMP, choline, iodide, zinc, and vitamin B12 may provide neuroprotection after perinatal HI.

Development of a combined solution of pyrimidine nucleotides with vitamin B6

Pyrimidine nucleotides, namely uridine monophosphate and cytidine monophosphate, play an important role in the cellular metabolism of nerve fibers. The combination of these nucleotides with pyridoxine hydrochloride (vitamin В6) in one dosage form will allow us to fully implement the strategy of the complex neurotropic pharmacotherapy in neuropathies of various origins. To develop a stable solution, an important step at the stage of the composition development is to study the compatibility of active substances (active pharmaceutical ingredients - APIs) in solution. Samples of binary solutions and solutions containing all active substances were prepared and examined. The API interaction was determined by various parameters – changes in color, transparency, рН, the total impurity content, etc. Based on a comprehensive study of the processes of the API dissolution the optimal pH limits of the solution required for the stable existence of a combination of substances with different pH values of the medium have been substantiated and experimentally confirmed. As a result of the research, the optimal pH value of the solution recommended is 4.0-4.8. In the composition of substances the amount of water can be in an adsorbed or crystallized, or combined form. This fact should be taken into account in order to correctly calculate the actual amounts of initial ingredients when preparing the solution. The nature of the water component of APIs was clarified when studying the phase composition of samples on a powder diffractometer. The studies conducted have allowed us to determine the directions of further research for developing the composition of an injection drug. This research is in choosing the optimal buffer system and excipients-antioxidants.

Analytical characterization of nucleotides and their concentration variation in drinking water treatment process

Nucleotides, as the basic building blocks of nucleic acids, widely exist in aqueous environment. In this study, we developed a solid phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) method for the analysis of 5′-adenosine monophosphate (AMP), 5′-uridine monophosphate (UMP), 5′-cytidine monophosphate (CMP) and 5′-guanosine monophosphate (GMP). The method achieved limits of detection (LODs) of 0.1–1.0 ng/L, and recoveries of 85–95% for the four tested nucleotides. The occurrence and concentrations of the four nucleotides in water from eight representative drinking water treatment and distribution systems in China were determined using this method. All four nucleotides were detectable in water treatment plant (WTP) influent and effluent, at concentrations of up to 30 ng/L and with occurrence frequency of around 90%. The concentrations of identified nucleotides increased 3–10 times after 10 km of water age in the water distribution system. Biological filters and coagulation increased the concentrations of nucleotides, conversely, active carbon, ozonation, and ultrafiltration membrane removed nucleotides in water. The effects of active carbon and coagulation were further confirmed using laboratory-controlled experiment. In addition, monochlorinated nucleotides were identified as the chlorination products of nucleotides.

Putative Nucleotide-Based Second Messengers in the Archaeal Model Organisms Haloferax volcanii and Sulfolobus acidocaldarius.

Research on nucleotide-based second messengers began in 1956 with the discovery of cyclic adenosine monophosphate (3′,5′-cAMP) by Earl Wilbur Sutherland and his co-workers. Since then, a broad variety of different signaling molecules composed of nucleotides has been discovered. These molecules fulfill crucial tasks in the context of intracellular signal transduction. The vast majority of the currently available knowledge about nucleotide-based second messengers originates from model organisms belonging either to the domain of eukaryotes or to the domain of bacteria, while the archaeal domain is significantly underrepresented in the field of nucleotide-based second messenger research. For several well-stablished eukaryotic and/or bacterial nucleotide-based second messengers, it is currently not clear whether these signaling molecules are present in archaea. In order to shed some light on this issue, this study analyzed cell extracts of two major archaeal model organisms, the euryarchaeon Haloferax volcanii and the crenarchaeon Sulfolobus acidocaldarius, using a modern mass spectrometry method to detect a broad variety of currently known nucleotide-based second messengers. The nucleotides 3′,5′-cAMP, cyclic guanosine monophosphate (3′,5′-cGMP), 5′-phosphoadenylyl-3′,5′-adenosine (5′-pApA), diadenosine tetraphosphate (Ap4A) as well as the 2′,3′-cyclic isomers of all four RNA building blocks (2′,3′-cNMPs) were present in both species. In addition, H. volcanii cell extracts also contain cyclic cytosine monophosphate (3′,5′-cCMP), cyclic uridine monophosphate (3′,5′-cUMP) and cyclic diadenosine monophosphate (3′,5′-c-di-AMP). The widely distributed bacterial second messengers cyclic diguanosine monophosphate (3′,5′-c-di-GMP) and guanosine (penta-)/tetraphosphate [(p)ppGpp] could not be detected. In summary, this study gives a comprehensive overview on the presence of a large set of currently established or putative nucleotide-based second messengers in an eury- and a crenarchaeal model organism.

Применение нуклеотидов при заболеваниях периферической нервной системы

Периферическая нейропатия (ПН) — общее состояние, распространенность которого составляет примерно 8 % у пожилых людей. Нейропатическая боль имеет значительную частоту в общей популяции и поражает более половины всех пациентов с ПН. Патофизиология ПН характеризуется поражением миелинопродуцирующих клеток Шванна в периферических нервах. Регенерация/защита миелиновой оболочки после поражения нерва является основным элементом восстановления при ПН. Проблема нейропатической боли приобретает все большую актуальность для клиницистов различных профилей, что связано с широким распространением патологии и трудностями в достижении стойкого терапевтического эффекта. Несмотря на большое количество фармакологических препаратов, рекомендованных для лечения пациентов с нейропатической болью, выбор оптимальной схемы лечения часто вызывает трудности у клиницистов. В течение последнего десятилетия достаточно активно во врачебной практике используется группа так называемых нуклеотидов. Накапливаются дополнительные сведения об эффектах этой группы препаратов и происходит постепенная трансформация, в том числе их состава. Так, в последнее время внимание исследователей уделяется изучению эффективности комбинации «уридинмонофосфат + витамин В12 (цианокобаламин) + фолиевая кислота», для которой характерен достаточно высокий профиль безопасности и хороший регенераторный потенциал. Цель этой статьи заключается в освещении механизмов действия и результатов клинического применения данной комбинации.