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Purinergic Signalling Dec 2022Pulmonary vascular tone is modulated by nucleotides, but which P2 receptors mediate these actions is largely unclear. The aim of this study, therefore, was to use...
Pulmonary vascular tone is modulated by nucleotides, but which P2 receptors mediate these actions is largely unclear. The aim of this study, therefore, was to use subtype-selective antagonists to determine the roles of individual P2Y receptor subtypes in nucleotide-evoked pulmonary vasodilation and vasoconstriction. Isometric tension was recorded from rat intrapulmonary artery rings (i.d. 200-500 µm) mounted on a wire myograph. Nucleotides evoked concentration- and endothelium-dependent vasodilation of precontracted tissues, but the concentration-response curves were shallow and did not reach a plateau. The selective P2Y antagonist, AR-C118925XX, inhibited uridine 5'-triphosphate (UTP)- but not adenosine 5'-triphosphate (ATP)-evoked relaxation, whereas the P2Y receptor antagonist, MRS2578, had no effect on UTP but inhibited relaxation elicited by uridine 5'-diphosphate (UDP). ATP-evoked relaxations were unaffected by the P2Y receptor antagonist, MRS2179, which substantially inhibited responses to adenosine 5'-diphosphate (ADP), and by the P2Y receptor antagonist, cangrelor, which potentiated responses to ADP. Both agonists were unaffected by CGS1593, an adenosine receptor antagonist. Finally, AR-C118925XX had no effect on vasoconstriction elicited by UTP or ATP at resting tone, although P2Y receptor mRNA was extracted from endothelium-denuded tissues using reverse transcription polymerase chain reaction with specific oligonucleotide primers. In conclusion, UTP elicits pulmonary vasodilation via P2Y receptors, whereas UDP acts at P2Y and ADP at P2Y receptors, respectively. How ATP induces vasodilation is unclear, but it does not involve P2Y, P2Y, P2Y, P2Y, or adenosine receptors. UTP- and ATP-evoked vasoconstriction was not mediated by P2Y receptors. Thus, this study advances our understanding of how nucleotides modulate pulmonary vascular tone.
Topics: Rats; Animals; Pulmonary Artery; Vasodilation; Uridine Triphosphate; Diphosphates; Adenosine Triphosphate; Uridine Diphosphate; Uridine; Receptors, Purinergic P2Y1; Receptors, Purinergic P2Y2
PubMed: 36018534
DOI: 10.1007/s11302-022-09895-x -
Plant Physiology Sep 2014Prenyl residues confer divergent biological activities such as antipathogenic and antiherbivorous activities on phenolic compounds, including flavonoids, coumarins, and...
Prenyl residues confer divergent biological activities such as antipathogenic and antiherbivorous activities on phenolic compounds, including flavonoids, coumarins, and xanthones. To date, about 1,000 prenylated phenolics have been isolated, with these compounds containing various prenyl residues. However, all currently described plant prenyltransferases (PTs) have been shown specific for dimethylallyl diphosphate as the prenyl donor, while most of the complementary DNAs encoding these genes have been isolated from the Leguminosae. In this study, we describe the identification of a novel PT gene from lemon (Citrus limon), ClPT1, belonging to the homogentisate PT family. This gene encodes a PT that differs from other known PTs, including flavonoid-specific PTs, in polypeptide sequence. This membrane-bound enzyme was specific for geranyl diphosphate as the prenyl donor and coumarin as the prenyl acceptor. Moreover, the gene product was targeted to plastid in plant cells. To our knowledge, this is the novel aromatic PT specific to geranyl diphosphate from citrus species.
Topics: Citrus; Dimethylallyltranstransferase; Diphosphates; Diterpenes; Molecular Sequence Data; Phylogeny; Plants, Genetically Modified; Plastids; Ruta; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid
PubMed: 25077796
DOI: 10.1104/pp.114.246892 -
Journal of Psychiatric Research Nov 2021Cytidine-5'-diphosphate choline (CDP-choline) has been suggested to exert neuroprotective and neuroreparative effects and may be beneficial for patients with stimulant... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Cytidine-5'-diphosphate choline (CDP-choline) has been suggested to exert neuroprotective and neuroreparative effects and may be beneficial for patients with stimulant dependence. This randomized, double-blind, placebo-controlled study in methamphetamine (MA) dependence investigated effects of CDP-choline on the brain structures and their associations with craving and MA use.
METHODS
MA users (n = 44) were randomized to receive 2 g/day of CDP-choline (n = 22) or placebo (n = 22) for 8 weeks. Patients underwent brain magnetic resonance imaging (MRI) at baseline and 8-week follow-up. Healthy individuals (n = 27) were also examined using brain MRI at the same interval. Voxel-based morphometry analysis was conducted to examine changes in gray matter (GM) volumes and their associations with craving and MA use.
RESULTS
Craving for MA was significantly reduced after the 8 week-treatment with CDP-choline (p = 0.01), but not with the placebo treatment (p = 0.10). There was no significant difference in the total number of MA-negative urine samples between the two groups (p = 0.19). With CDP-choline treatment, GM volumes in the left middle frontal gyrus (p = 0.001), right hippocampus (p = 0.009), and left precuneus (p = 0.001) were significantly increased compared to the placebo and control groups. Increased GM volumes in the left middle frontal gyrus with CDP-choline treatment were associated with reduced craving for MA (Spearman's ρ = -0.56, p = 0.03). In addition, the right hippocampal volume increases were positively associated with the total number of MA-negative urine results in the CDP-choline group (Spearman's ρ = 0.67, p = 0.006).
CONCLUSION
Our findings suggest that CDP-choline may increase GM volumes of MA-dependent patients, which may be related to decreases in MA use and craving.
Topics: Amphetamine-Related Disorders; Cytidine; Cytidine Diphosphate Choline; Diphosphates; Gray Matter; Humans; Methamphetamine
PubMed: 34507102
DOI: 10.1016/j.jpsychires.2021.09.006 -
Biological & Pharmaceutical Bulletin 2021Bisphosphonates (BPs) are major anti-bone-resorptive drugs. Among them, the nitrogen-containing BPs (NBPs) exhibit much stronger anti-bone-resorptive activities than...
Bisphosphonates (BPs) are major anti-bone-resorptive drugs. Among them, the nitrogen-containing BPs (NBPs) exhibit much stronger anti-bone-resorptive activities than non-nitrogen-containing BPs (non-NBPs). However, BP-related osteonecrosis of the jaw (BRONJ) has been increasing without effective strategies for its prevention or treatment. The release of NBPs (but not non-NBPs) from NBP-accumulated jawbones has been supposed to cause BRONJ, even though non-NBPs (such as etidronate (Eti) and clodronate (Clo)) are given at very high doses because of their low anti-bone-resorptive activities. Our murine experiments have demonstrated that NBPs cause inflammation/necrosis at the injection site, and that Eti and Clo can reduce or prevent the inflammatory/necrotic effects of NBPs by inhibiting their entry into soft-tissue cells. In addition, our preliminary clinical studies suggest that Eti may be useful for treating BRONJ. Notably, Eti, when administered together with an NBP, reduces the latter's anti-bone-resorptive effect. Here, on the basis of the above background, we examined and compared in vitro interactions of NBPs, non-NBPs, and related substances with hydroxyapatite (HA), and obtained the following results. (i) NBPs bind rapidly to HA under pH-neutral conditions. (ii) At high concentrations, Eti and Clo inhibit NBP-binding to HA and rapidly expel HA-bound NBPs (potency Eti>>Clo). (iii) Pyrophosphate also inhibits NBP-binding to HA and expels HA-bound NBPs. Based on these results and those reported previously, we discuss (i) possible anti-BRONJ strategies involving the use of Eti and/or Clo to reduce jawbone-accumulated NBPs, and (ii) a possible involvement of pyrophosphate-mediated release of NBPs as a cause of BRONJ.
Topics: Calcium; Diphosphates; Diphosphonates; Durapatite; Hydrogen-Ion Concentration; Magnesium; Nitrogen
PubMed: 34719644
DOI: 10.1248/bpb.b21-00320 -
The Journal of Cell Biology Oct 2023Mitochondrial fusion plays an important role in both their structure and function. In this issue, Su et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202301091)...
Mitochondrial fusion plays an important role in both their structure and function. In this issue, Su et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202301091) report that a nucleoside diphosphate kinase, NME3, facilitates mitochondrial tethering prior to fusion through its direct membrane-binding and hexamerization but not its kinase activity.
Topics: Diphosphates; Mitochondria; Mitochondrial Dynamics; Nucleotides; Phosphorylation; Humans; NM23 Nucleoside Diphosphate Kinases
PubMed: 37707790
DOI: 10.1083/jcb.202309037 -
Nature Communications May 2018Almost all kinases utilize ATP as their phosphate donor, while a few kinases utilize pyrophosphate (PPi) instead. PPi-dependent kinases are often homologous to their...
Almost all kinases utilize ATP as their phosphate donor, while a few kinases utilize pyrophosphate (PPi) instead. PPi-dependent kinases are often homologous to their ATP-dependent counterparts, but determinants of their different donor specificities remain unclear. We identify a PPi-dependent member of the ribokinase family, which differs from known PPi-dependent kinases, and elucidate its PPi-binding mode based on the crystal structures. Structural comparison and sequence alignment reveal five important residues: three basic residues specifically recognizing PPi and two large hydrophobic residues occluding a part of the ATP-binding pocket. Two of the three basic residues adapt a conserved motif of the ribokinase family for the PPi binding. Using these five key residues as a signature pattern, we discover additional PPi-specific members of the ribokinase family, and thus conclude that these residues are the determinants of PPi-specific binding. Introduction of these residues may enable transformation of ATP-dependent ribokinase family members into PPi-dependent enzymes.
Topics: Amino Acid Sequence; Amino Acids; Base Sequence; Binding Sites; Crystallography, X-Ray; Diphosphates; Kinetics; Models, Molecular; Mutation; Phosphotransferases (Alcohol Group Acceptor); Protein Domains; Sequence Homology, Amino Acid
PubMed: 29720581
DOI: 10.1038/s41467-018-04201-z -
Journal of the Royal College of... Oct 1984
Topics: Angiocardiography; Coronary Angiography; Diphosphates; Echocardiography; Heart; Heart Diseases; Humans; Magnetic Resonance Spectroscopy; Radiography, Thoracic; Radionuclide Imaging; Subtraction Technique; Technetium; Technetium Tc 99m Pyrophosphate; Tomography, X-Ray Computed
PubMed: 6094801
DOI: No ID Found -
Chemical & Pharmaceutical Bulletin 2022This study aimed to evaluate the interspecies difference in metabolism of mulberrin and examine the interaction between mulberrin and CYP enzymes or recombinant human...
This study aimed to evaluate the interspecies difference in metabolism of mulberrin and examine the interaction between mulberrin and CYP enzymes or recombinant human uridine 5'-diphosphate (UDP)-glucuronosyltransferase (UGT) enzymes. Liver microsomes from human (HLMs), Beagle dog (DLMs), minipig (PLMs), monkey (MLMs), rabbit (RLMs), rat (RAMs), and mouse (MIMs) were used to investigate metabolic diversity among different species. Additionally, recombinant human supersomes were used to confirm that metabolic enzymes are involved in the biotransformation of mulberrin. We also evaluated the influence of mulberrin on protein expression by Western blot analysis. Mulberrin metabolism showed significant interspecies differences. We found four and two metabolites in phase I and II reaction systems, respectively. In phase I metabolism profiles of mulberrin for HLMs, PLMs and MLMs conformed to the classic Michaelis-Menten kinetics, RAMs and MIMs followed biphasic kinetics; phase II reaction of mulberrin in HLMs, DLMs, PLMs, MLMs, RLMs, RAMs and MIMs followed biphasic kinetics. UGT1A1 were the major CYP isoforms responsible for the metabolism of mulberrin. Mulberrin showed potent inhibitory effects against CYP3A4, CYP2C9, CYP2E1, UGT1A1, UGT1A3 and UGT2B7 with IC values of 54.21, 9.93, 39.12, 3.84, 2.01, 16.36 µM, respectively. According to Western blot analysis, mulberrin can upregulate the protein expression of CYP2C19, and downregulate the expression levels of CYP3A5 and CYP2C9 in HepG2 cells as concentration increased. The interspecies comparisons can help find other species with metabolic pathways similar to those in humans for future in vivo studies.
Topics: Animals; Benzene Derivatives; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP2C9; Cytochrome P-450 CYP2E1; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Diphosphates; Dogs; Glucuronosyltransferase; Humans; Mice; Microsomes, Liver; Protein Isoforms; Rabbits; Rats; Species Specificity; Swine; Swine, Miniature; Uridine; Uridine Diphosphate
PubMed: 36184449
DOI: 10.1248/cpb.c22-00093 -
Chembiochem : a European Journal of... Nov 2022Two terpene cyclases were used as biocatalytic tool, namely, limonene synthase from Cannabis sativa (CLS) and 5-epi-aristolochene synthase (TEAS) from Nicotiana tabacum....
Two terpene cyclases were used as biocatalytic tool, namely, limonene synthase from Cannabis sativa (CLS) and 5-epi-aristolochene synthase (TEAS) from Nicotiana tabacum. They showed significant substrate flexibility towards non-natural prenyl diphosphates to form novel terpenoids, including core oxa- and thia-heterocycles and alkyne-modified terpenoids. We elucidated the structures of five novel monoterpene-analogues and a known sesquiterpene-analogue. These results reflected the terpene synthases' ability and promiscuity to broaden the pool of terpenoids with structurally complex analogues. Docking studies highlight an on-off conversion of the unnatural substrates.
Topics: Terpenes; Diphosphates; Odorants; Alkynes; Alkyl and Aryl Transferases; Perfume; Biotransformation
PubMed: 36173145
DOI: 10.1002/cbic.202200211 -
Proceedings of the National Academy of... May 2012IspG is a 4Fe4S protein involved in isoprenoid biosynthesis. Most bacterial IspGs contain two domains: a TIM barrel (A) and a 4Fe4S domain (B), but in plants and malaria...
IspG is a 4Fe4S protein involved in isoprenoid biosynthesis. Most bacterial IspGs contain two domains: a TIM barrel (A) and a 4Fe4S domain (B), but in plants and malaria parasites, there is a large insert domain (A*) whose structure and function are unknown. We show that bacterial IspGs function in solution as (AB)(2) dimers and that mutations in either both A or both B domains block activity. Chimeras harboring an A-mutation in one chain and a B-mutation in the other have 50% of the activity seen in wild-type protein, because there is still one catalytically active AB domain. However, a plant IspG functions as an AA*B monomer. We propose, using computational modeling and electron microscopy, that the A* insert domain has a TIM barrel structure that interacts with the A domain. This structural arrangement enables the A and B domains to interact in a "cup and ball" manner during catalysis, just as in the bacterial systems. EPR/HYSCORE spectra of reaction intermediate, product, and inhibitor ligands bound to both two and three domain proteins are identical, indicating the same local electronic structure, and computational docking indicates these ligands bridge both A and B domains. Overall, the results are of broad general interest because they indicate the insert domain in three-domain IspGs is a second TIM barrel that plays a structural role and that the pattern of inhibition of both two and three domain proteins are the same, results that can be expected to be of use in drug design.
Topics: Alkynes; Amino Acid Sequence; Bacterial Proteins; Binding Sites; Biocatalysis; Computer Simulation; Diphosphates; Electron Spin Resonance Spectroscopy; Iron-Sulfur Proteins; Ligands; Microscopy, Electron; Models, Molecular; Molecular Sequence Data; Mutation; Protein Binding; Protein Multimerization; Protein Structure, Quaternary; Protein Structure, Tertiary; Sequence Homology, Amino Acid
PubMed: 22586085
DOI: 10.1073/pnas.1121107109