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Oncogene Apr 2023The NUDIX hydrolase NUDT22 converts UDP-glucose into glucose-1-phosphate and the pyrimidine nucleotide uridine monophosphate but a biological significance for this...
The NUDIX hydrolase NUDT22 converts UDP-glucose into glucose-1-phosphate and the pyrimidine nucleotide uridine monophosphate but a biological significance for this biochemical reaction has not yet been established. Glucose-1-phosphate is an important metabolite for energy and biomass production through glycolysis and nucleotides required for DNA replication are produced through energetically expensive de novo or energy-efficient salvage pathways. Here, we describe p53-regulated pyrimidine salvage through NUDT22-dependent hydrolysis of UDP-glucose to maintain cancer cell growth and to prevent replication stress. NUDT22 expression is consistently elevated in cancer tissues and high NUDT22 expression correlates with worse survival outcomes in patients indicating an increased dependency of cancer cells to NUDT22. Furthermore, we show that NUDT22 transcription is induced after inhibition of glycolysis, MYC-mediated oncogenic stress, and DNA damage directly through p53. NUDT22-deficient cancer cells suffer from growth retardation, S-phase delay, and slower DNA replication fork speed. Uridine supplementation rescues replication fork progression and alleviates replication stress and DNA damage. Conversely, NUDT22 deficiency sensitizes cells to de novo pyrimidine synthesis inhibition in vitro and reduces cancer growth in vivo. In conclusion, NUDT22 maintains pyrimidine supply in cancer cells and depletion of NUDT22 leads to genome instability. Targeting NUDT22 therefore has high potential for therapeutic applications in cancer therapy.
Topics: Humans; Glucose; Neoplasms; Pyrimidines; Tumor Suppressor Protein p53; Uridine; Uridine Diphosphate
PubMed: 36871087
DOI: 10.1038/s41388-023-02643-4 -
Neuropharmacology Nov 2023Uridine 5'-diphosphoglucose (UDP-G) as a preferential agonist, but also other UDP-sugars, such as UDP galactose, function as extracellular signaling molecules under... (Review)
Review
Uridine 5'-diphosphoglucose (UDP-G) as a preferential agonist, but also other UDP-sugars, such as UDP galactose, function as extracellular signaling molecules under conditions of cell injury and apoptosis. Consequently, UDP-G is regarded to function as a damage-associated molecular pattern (DAMP), regulating immune responses. UDP-G promotes neutrophil recruitment, leading to the release of pro-inflammatory chemokines. As a potent endogenous agonist with the highest affinity for the P2Y receptor (R), it accomplishes an exclusive relationship between P2YRs in regulating inflammation via cyclic adenosine monophosphate (cAMP), nod-like receptor protein 3 (NLRP3) inflammasome, mitogen-activated protein kinases (MAPKs), and signal transducer and activator of transcription 1 (STAT1) pathways. In this review, we initially present a brief introduction into the expression and function of P2YRs in combination with UDP-G. Subsequently, we summarize emerging roles of UDP-G/P2YR signaling pathways that modulate inflammatory responses in diverse systems, and discuss the underlying mechanisms of P2YR activation in inflammation-related diseases. Moreover, we also refer to the applications as well as effects of novel agonists/antagonists of P2YRs in inflammatory conditions. In conclusion, due to the role of the P2YR in the immune system and inflammatory pathways, it may represent a novel target for anti-inflammatory therapy.
Topics: Humans; Receptors, Purinergic P2; Uridine Diphosphate Glucose; Uridine Diphosphate Sugars; Inflammation; Glucose
PubMed: 37423482
DOI: 10.1016/j.neuropharm.2023.109655 -
Cancer Letters Jan 2023Inhibitors of dihydroorotate dehydrogenase (DHODH), a key enzyme for de novo synthesis of pyrimidine nucleotides, have failed in clinical trials for various cancers...
Inhibitors of dihydroorotate dehydrogenase (DHODH), a key enzyme for de novo synthesis of pyrimidine nucleotides, have failed in clinical trials for various cancers despite robust efficacy in preclinical animal models. To probe for druggable mediators of DHODH inhibitor resistance, we performed a combination screen with a small molecule library against pancreatic cancer cell lines that are highly resistant to the DHODH inhibitor brequinar (BQ). The screen revealed that CNX-774, a preclinical Bruton tyrosine kinase (BTK) inhibitor, sensitizes resistant cell lines to BQ. Mechanistic studies showed that this effect is independent of BTK and instead results from inhibition of equilibrative nucleoside transporter 1 (ENT1) by CNX-774. We show that ENT1 mediates BQ resistance by taking up extracellular uridine, which is salvaged to generate pyrimidine nucleotides in a DHODH-independent manner. In BQ-resistant cell lines, BQ monotherapy slowed proliferation and caused modest pyrimidine nucleotide depletion, whereas combination treatment with BQ and CNX-774 led to profound cell viability loss and pyrimidine starvation. We also identify N-acetylneuraminic acid accumulation as a potential marker of the therapeutic efficacy of DHODH inhibitors. In an aggressive, immunocompetent pancreatic cancer mouse model, combined targeting of DHODH and ENT1 dramatically suppressed tumor growth and prolonged mouse survival. Overall, our study defines CNX-774 as a previously uncharacterized ENT1 inhibitor and provides strong proof of concept support for dual targeting of DHODH and ENT1 in pancreatic cancer.
Topics: Mice; Animals; Dihydroorotate Dehydrogenase; Equilibrative Nucleoside Transporter 1; Oxidoreductases Acting on CH-CH Group Donors; Pyrimidines; Enzyme Inhibitors; Pancreatic Neoplasms; Pyrimidine Nucleotides
PubMed: 36341997
DOI: 10.1016/j.canlet.2022.215981 -
International Journal of Molecular... Mar 2023Ocular neurodegenerative diseases such as glaucoma, diabetic retinopathy, and age-related macular degeneration are common retinal diseases responsible for most of the... (Review)
Review
Ocular neurodegenerative diseases such as glaucoma, diabetic retinopathy, and age-related macular degeneration are common retinal diseases responsible for most of the blindness causes in the working-age and elderly populations in developed countries. Many of the current treatments used in these pathologies fail to stop or slow the progression of the disease. Therefore, other types of treatments with neuroprotective characteristics may be necessary to allow a more satisfactory management of the disease. Citicoline and coenzyme Q10 are molecules that have neuroprotective, antioxidant, and anti-inflammatory properties, and their use could have a beneficial effect in ocular neurodegenerative pathologies. This review provides a compilation, mainly from the last 10 years, of the main studies that have been published on the use of these drugs in these neurodegenerative diseases of the retina, analyzing the usefulness of these drugs in these pathologies.
Topics: Humans; Aged; Cytidine Diphosphate Choline; Retina; Retinal Diseases; Neurodegenerative Diseases
PubMed: 36982157
DOI: 10.3390/ijms24065072 -
Structure-Activity Relationship of 3-Methylcytidine-5'-α,β-methylenediphosphates as CD73 Inhibitors.Journal of Medicinal Chemistry Feb 2022We recently reported -substituted 3-methylcytidine-5'-α,β-methylenediphosphates as CD73 inhibitors, potentially useful in cancer immunotherapy. We now expand the...
We recently reported -substituted 3-methylcytidine-5'-α,β-methylenediphosphates as CD73 inhibitors, potentially useful in cancer immunotherapy. We now expand the structure-activity relationship of pyrimidine nucleotides as human CD73 inhibitors. 4-Chloro (MRS4598 ; = 0.673 nM) and 4-iodo (MRS4620 ; = 0.436 nM) substitution of the -benzyloxy group decreased by ∼20-fold. Primary alkylamine derivatives coupled through a -amido group with a varying methylene chain length ( and ) were functionalized congeners, for subsequent conjugation to carrier or reporter moieties. X-ray structures of hCD73 with two inhibitors indicated a ribose ring conformational adaptation, and the benzyloxyimino group ( configuration) binds to the same region (between the C-terminal and N-terminal domains) as -benzyl groups in adenine inhibitors. Molecular dynamics identified stabilizing interactions and predicted conformational diversity. Thus, by -benzyloxy substitution, we have greatly enhanced the inhibitory potency and added functionality enabling molecular probes. Their potential as anticancer drugs was confirmed by blocking CD73 activity in tumor tissues in situ.
Topics: 5'-Nucleotidase; Adult; Cytosine Nucleotides; Diphosphonates; Enzyme Inhibitors; GPI-Linked Proteins; Humans; Male; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Structure; Neoplasms; Palatine Tonsil; Protein Binding; Structure-Activity Relationship
PubMed: 35080883
DOI: 10.1021/acs.jmedchem.1c01852 -
FEBS Letters Sep 2014The degradation and biological role of the cyclic pyrimidine nucleotide cCMP is largely elusive. We investigated nucleoside 3',5'-cyclic monophosphate (cNMP) specificity...
The degradation and biological role of the cyclic pyrimidine nucleotide cCMP is largely elusive. We investigated nucleoside 3',5'-cyclic monophosphate (cNMP) specificity of six different recombinant phosphodiesterases (PDEs) by using a highly-sensitive HPLC-MS/MS detection method. PDE7A1 was the only enzyme that hydrolyzed significant amounts of cCMP. Enzyme kinetic studies using purified GST-tagged truncated PDE7A1 revealed a cCMP KM value of 135 ± 19 μM. The Vmax for cCMP hydrolysis reached 745 ± 27 nmol/(minmg), which is about 6-fold higher than the corresponding velocity for adenosine 3',5'-cyclic monophosphate (cAMP) degradation. In summary, PDE7A is a high-speed and low-affinity PDE for cCMP.
Topics: Animals; Cell Line, Tumor; Cyclic AMP; Cyclic CMP; Cyclic Nucleotide Phosphodiesterases, Type 7; Humans; Hydrolysis; Kinetics; Nitro Compounds; Phosphodiesterase Inhibitors; Second Messenger Systems; Sf9 Cells; Spodoptera; Substrate Specificity; Sulfonamides
PubMed: 25128584
DOI: 10.1016/j.febslet.2014.08.005 -
Clinical Interventions in Aging 2023Neuroprotective drugs such as citicoline could improve cognitive performance and quality of life. We studied the effect of citicoline treatment and its association with... (Observational Study)
Observational Study
INTRODUCTION
Neuroprotective drugs such as citicoline could improve cognitive performance and quality of life. We studied the effect of citicoline treatment and its association with Vascular Risk Factors (VRF) and APOE on cognition in patients with Subjective Cognitive Complaints (SCC) and Mild Cognitive Impairment (MCI).
METHODS
This is an observational and prospective study with citicoline during 12 months follow-up. Eighty-one subjects who met criteria for SCC/MCI, aged 50-75 years with VRF were included and prescribed citicoline 1g/day. Subjects with previous cognitive impairment and any other central nervous system affection were excluded. Wilcoxon Signed Ranks test and paired samples -test were used to analyze the change in neuropsychological performance.
RESULTS
Mean age of the sample was 68.2 (SD 6.8) years and 26 (32.09%) were females. Fifteen subjects (24.6%) were APOE-ε4 carriers, fifty-six (76.7%) had hypertension, fifty-eight (79.5%) had dyslipidemia, twenty-one (28.8%) had diabetes mellitus and twenty-six (35.6%) had cardiopathy. Thirty-two (43.8%) subjects were diagnosed as SCC and forty-one (56.16%) as MCI. During the follow-up, Tweny-six patients (81.25%) in the group of SCC remained stable, six subjects (18.8%) converted to MCI. Twelve patients (29.9%) with MCI reverted to SCC and twenty-nine patients (70.7%) remained stable. At follow-up, SCC subjects had an improvement in the global language domain (p=0.03), naming (p<0.001), attention (p=0.01) and visuospatial abilities (p<0.01). MCI group showed an improvement in the screening test (p=0.03), delayed memory (p<0.01), global cognition (p=0.04) and in cognitive flexibility (p=0.03). Presence of APOE-ε4 had no impact on the above findings.
DISCUSSION
SCC subjects showed an improvement in language and attention domains, while those with MCI performed better after 12 months in total scores of MoCA and RBANS domains, some converting back to SCC. This supports the idea that citicoline may prevent cognitive decline in patients with cognitive deficits.
Topics: Female; Humans; Aged; Male; Cytidine Diphosphate Choline; Prospective Studies; Quality of Life; Cognitive Dysfunction; Cerebrovascular Disorders; Apolipoproteins E
PubMed: 37489128
DOI: 10.2147/CIA.S409994 -
Trends in Molecular Medicine Oct 2018Innovations in epitranscriptomics have resulted in the identification of more than 160 RNA modifications to date. These developments, together with the recent discovery... (Review)
Review
Innovations in epitranscriptomics have resulted in the identification of more than 160 RNA modifications to date. These developments, together with the recent discovery of writers, readers, and erasers of modifications occurring across a wide range of RNAs and tissue types, have led to a surge in integrative approaches for transcriptome-wide mapping of modifications and protein-RNA interaction profiles of epitranscriptome players. RNA modification maps and crosstalk between them have begun to elucidate the role of modifications as signaling switches, entertaining the notion of an epitranscriptomic code as a driver of the post-transcriptional fate of RNA. Emerging single-molecule sequencing technologies and development of antibodies specific to various RNA modifications could enable charting of transcript-specific epitranscriptomic marks across cell types and their alterations in disease.
Topics: Cardiovascular Diseases; Congenital Abnormalities; Epigenesis, Genetic; High-Throughput Nucleotide Sequencing; Humans; Metabolic Diseases; Methylation; Mitochondrial Diseases; Neoplasms; Nervous System Diseases; Purine Nucleotides; Pyrimidine Nucleotides; RNA; RNA Processing, Post-Transcriptional; Transcriptome
PubMed: 30120023
DOI: 10.1016/j.molmed.2018.07.010 -
Current Opinion in Biotechnology Dec 2017The development of broad-spectrum, host-acting antiviral therapies remains an important but elusive goal in anti-infective drug discovery. To replicate efficiently,... (Review)
Review
The development of broad-spectrum, host-acting antiviral therapies remains an important but elusive goal in anti-infective drug discovery. To replicate efficiently, viruses not only depend on their hosts for an adequate supply of pyrimidine nucleotides, but also up-regulate pyrimidine nucleotide biosynthesis in infected cells. In this review, we outline our understanding of mammalian de novo and salvage metabolic pathways for pyrimidine nucleotide biosynthesis. The available spectrum of experimental and FDA-approved drugs that modulate individual steps in these metabolic pathways is also summarized. The logic of a host-acting combination antiviral therapy comprised of inhibitors of dihydroorotate dehydrogenase and uridine/cytidine kinase is discussed.
Topics: Antiviral Agents; Dihydroorotate Dehydrogenase; Enzyme Inhibitors; Humans; Oxidoreductases Acting on CH-CH Group Donors; Pyrimidine Nucleotides; Viruses
PubMed: 28458037
DOI: 10.1016/j.copbio.2017.03.010 -
Physical Chemistry Chemical Physics :... May 2015Photolyases, a class of flavoproteins, use blue light to repair two types of ultraviolet-induced DNA damage, a cyclobutane pyrimidine dimer (CPD) and a... (Review)
Review
Photolyases, a class of flavoproteins, use blue light to repair two types of ultraviolet-induced DNA damage, a cyclobutane pyrimidine dimer (CPD) and a pyrimidine-pyrimidone (6-4) photoproduct (6-4PP). In this perspective, we review the recent progress in the repair dynamics and mechanisms of both types of DNA restoration by photolyases. We first report the spectroscopic characterization of flavin in various redox states and the active-site solvation dynamics in photolyases. We then systematically summarize the detailed repair dynamics of damaged DNA by photolyases and a biomimetic system through resolving all elementary steps on ultrafast timescales, including multiple intermolecular electron- and proton-transfer reactions and bond-breaking and -making processes. We determined the unique electron tunneling pathways, identified the key functional residues and revealed the molecular origin of high repair efficiency, and thus elucidate the molecular mechanisms and repair photocycles at the most fundamental level. We finally conclude that the active sites of photolyases, unlike the aqueous solution for the biomimetic system, provide a unique electrostatic environment and local flexibility and thus a dedicated synergy for all elementary dynamics to maximize the repair efficiency. This repair photomachine is the first enzyme that the entire functional evolution is completely mapped out in real time.
Topics: Animals; Catalytic Domain; DNA; DNA Damage; DNA Repair; Deoxyribodipyrimidine Photo-Lyase; Humans; Light; Models, Molecular; Mutation; Protein Conformation; Pyrimidine Dimers; Ultraviolet Rays
PubMed: 25870862
DOI: 10.1039/c4cp05286b