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Molecules (Basel, Switzerland) Feb 2023Upregulated CXCR2 signalling is found in numerous inflammatory, autoimmune and neurodegenerative diseases, as well as in cancer. Consequently, CXCR2 antagonism is a...
Upregulated CXCR2 signalling is found in numerous inflammatory, autoimmune and neurodegenerative diseases, as well as in cancer. Consequently, CXCR2 antagonism is a promising therapeutic strategy for treatment of these disorders. We previously identified, via scaffold hopping, a pyrido[3,4-]pyrimidine analogue as a promising CXCR2 antagonist with an IC value of 0.11 µM in a kinetic fluorescence-based calcium mobilization assay. This study aims at exploring the structure-activity relationship (SAR) and improving the CXCR2 antagonistic potency of this pyrido[3,4-]pyrimidine via systematic structural modifications of the substitution pattern. Almost all new analogues completely lacked the CXCR2 antagonism, the exception being a 6-furanyl-pyrido[3,4-]pyrimidine analogue (compound ) that is endowed with similar antagonistic potency as the original hit.
Topics: Humans; Neoplasms; Pyrimidines; Receptors, Chemokine; Structure-Activity Relationship; Receptors, Interleukin-8B
PubMed: 36903345
DOI: 10.3390/molecules28052099 -
Journal of Medicinal Chemistry Feb 2019The clinical evidence for the success of tyrosine kinase inhibitors in combination with microtubule-targeting agents prompted us to design and develop single agents that...
Design, Synthesis, and Biological Evaluation of 6-Substituted Thieno[3,2- d]pyrimidine Analogues as Dual Epidermal Growth Factor Receptor Kinase and Microtubule Inhibitors.
The clinical evidence for the success of tyrosine kinase inhibitors in combination with microtubule-targeting agents prompted us to design and develop single agents that possess both epidermal growth factor receptor (EGFR) kinase and tubulin polymerization inhibitory properties. A series of 6-aryl/heteroaryl-4-(3',4',5'-trimethoxyanilino)thieno[3,2- d]pyrimidine derivatives were discovered as novel dual tubulin polymerization and EGFR kinase inhibitors. The 4-(3',4',5'-trimethoxyanilino)-6-( p-tolyl)thieno[3,2- d]pyrimidine derivative 6g was the most potent compound of the series as an antiproliferative agent, with half-maximal inhibitory concentration (IC) values in the single- or double-digit nanomolar range. Compound 6g bound to tubulin in the colchicine site and inhibited tubulin assembly with an IC value of 0.71 μM, and 6g inhibited EGFR activity with an IC value of 30 nM. Our data suggested that the excellent in vitro and in vivo profile of 6g may be derived from its dual inhibition of tubulin polymerization and EGFR kinase.
Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Colchicine; Drug Design; Drug Evaluation, Preclinical; Enzyme Activation; ErbB Receptors; HeLa Cells; Humans; Membrane Potential, Mitochondrial; Microtubules; Poly(ADP-ribose) Polymerases; Polymerization; Pyrimidines; Reactive Oxygen Species; Tubulin; Vascular Endothelial Growth Factor Receptor-2
PubMed: 30633509
DOI: 10.1021/acs.jmedchem.8b01391 -
Molecules (Basel, Switzerland) Nov 2020Convenient and efficient routes to construct hybrid molecules containing diterpene alkaloid lappaconitine and pyrimidine fragments are reported. One route takes place...
Convenient and efficient routes to construct hybrid molecules containing diterpene alkaloid lappaconitine and pyrimidine fragments are reported. One route takes place via first converting of lappaconitine to 1-ethynyl-lappaconitine, followed by the Sonogashira cross-coupling-cyclocondensation sequences. The other involves the palladium-catalyzed carbonylative Sonogashira reaction of 5'-iodolappaconitine with aryl acetylene and Mo (CO) as the CO source in acetonitrile and subsequent cyclocondensation reaction of the generated alkynone with amidines. The reaction proceeded cleanly in the presence of the PdCl-(1-Ad)PBn∙HBr catalytic system. The protocol provides mild reaction conditions, high yields, and high atom and step-economy. Pharmacological screening of lappaconitine-pyrimidine hybrids for antinociceptive activity in vivo revealed that these compounds possessed high activity in experimental pain models, which was dependent on the nature of the substituent in the 2 and 6 positions of the pyrimidine nucleus. Docking studies were undertaken to gain insight into the possible binding mode of these compounds with the voltage-gated sodium channel 1.7. The moderate toxicity of the leading compound (50% lethal dose (LD) value was more than 600 mg/kg in vivo) and cytotoxicity to cancer cell lines in vitro encouraged the further design of therapeutically relevant analogues based on this novel type of lappaconitine-pyrimidine hybrids.
Topics: Aconitine; Analgesics; Animals; Male; Mice; Nociception; Pain; Pyrimidines; ortho-Aminobenzoates
PubMed: 33261161
DOI: 10.3390/molecules25235578 -
Hepatology (Baltimore, Md.) Oct 2017Hepatic cystogenesis in polycystic liver disease is associated with increased levels of cyclic adenosine monophosphate (cAMP) in cholangiocytes lining liver cysts....
UNLABELLED
Hepatic cystogenesis in polycystic liver disease is associated with increased levels of cyclic adenosine monophosphate (cAMP) in cholangiocytes lining liver cysts. Takeda G protein receptor 5 (TGR5), a G protein-coupled bile acid receptor, is linked to cAMP and expressed in cholangiocytes. Therefore, we hypothesized that TGR5 might contribute to disease progression. We examined expression of TGR5 and Gα proteins in cultured cholangiocytes and in livers of animal models and humans with polycystic liver disease. In vitro, we assessed cholangiocyte proliferation, cAMP levels, and cyst growth in response to (1) TGR5 agonists (taurolithocholic acid, oleanolic acid [OA], and two synthetic compounds), (2) a novel TGR5 antagonist (m-tolyl 5-chloro-2-[ethylsulfonyl] pyrimidine-4-carboxylate [SBI-115]), and (3) a combination of SBI-115 and pasireotide, a somatostatin receptor analogue. In vivo, we examined hepatic cystogenesis in OA-treated polycystic kidney rats and after genetic elimination of TGR5 in double mutant TGR5 ;Pkhd1 mice. Compared to control, expression of TGR5 and Gα (but not Gα and Gα ) proteins was increased 2-fold to 3-fold in cystic cholangiocytes in vitro and in vivo. In vitro, TGR5 stimulation enhanced cAMP production, cell proliferation, and cyst growth by ∼40%; these effects were abolished after TGR5 reduction by short hairpin RNA. OA increased cystogenesis in polycystic kidney rats by 35%; in contrast, hepatic cystic areas were decreased by 45% in TGR5-deficient TGR5 ;Pkhd1 mice. TGR5 expression and its colocalization with Gα were increased ∼2-fold upon OA treatment. Levels of cAMP, cell proliferation, and cyst growth in vitro were decreased by ∼30% in cystic cholangiocytes after treatment with SBI-115 alone and by ∼50% when SBI-115 was combined with pasireotide.
CONCLUSION
TGR5 contributes to hepatic cystogenesis by increasing cAMP and enhancing cholangiocyte proliferation; our data suggest that a TGR5 antagonist alone or concurrently with somatostatin receptor agonists represents a potential therapeutic approach in polycystic liver disease. (Hepatology 2017;66:1197-1218).
Topics: Adaptor Proteins, Signal Transducing; Animals; Cell Proliferation; Cyclic AMP; Cysts; Drug Evaluation, Preclinical; Drug Therapy, Combination; GTP-Binding Protein alpha Subunits, Gs; Humans; Liver Diseases; Mice; Oleanolic Acid; Polycystic Kidney Diseases; Primary Cell Culture; Pyrimidines; Rats; Receptors, G-Protein-Coupled; Somatostatin
PubMed: 28543567
DOI: 10.1002/hep.29284 -
MBio Oct 2017Vitamin B (thiamin) is a cofactor for critical enzymatic processes and is scarce in surface oceans. Several eukaryotic marine algal species thought to rely on exogenous...
Vitamin B (thiamin) is a cofactor for critical enzymatic processes and is scarce in surface oceans. Several eukaryotic marine algal species thought to rely on exogenous thiamin are now known to grow equally well on the precursor 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP), including the haptophyte Because the thiamin biosynthetic capacities of the diverse and ecologically important haptophyte lineage are otherwise unknown, we investigated the pathway in transcriptomes and two genomes from 30 species representing six taxonomic orders. HMP synthase is missing in data from all studied taxa, but the pathway is otherwise complete, with some enzymatic variations. Experiments on axenic species from three orders demonstrated that equivalent growth rates were supported by 1 µM HMP or thiamin amendment. Cellular thiamin quotas were quantified in the oceanic phytoplankter using the thiochrome assay. exhibited luxury storage in standard algal medium [(1.16 ± 0.18) × 10 pmol thiamin cell], whereas quotas in cultures grown under more environmentally relevant thiamin and HMP supplies [(2.22 ± 0.07) × 10 or (1.58 ± 0.14) × 10 pmol thiamin cell, respectively] were significantly lower than luxury values and prior estimates. HMP and its salvage-related analog 4-amino-5-aminomethyl-2-methylpyrimidine (AmMP) supported higher growth than thiamin under environmentally relevant supply levels. These compounds also sustained growth of the stramenopile alga Together with identification of a salvage protein subfamily (TENA_E) in multiple phytoplankton, the results indicate that salvaged AmMP and exogenously acquired HMP are used by several groups for thiamin production. Our studies highlight the potential importance of thiamin pathway intermediates and their analogs in shaping phytoplankton community structure. The concept that vitamin B (thiamin) availability in seawater controls the productivity and structure of eukaryotic phytoplankton communities has been discussed for half a century. We examined B biosynthesis and salvage pathways in diverse phytoplankton species. These comparative genomic analyses as well as experiments show that phytoplankton thought to require exogenous B not only utilize intermediate compounds to meet this need but also exhibit stronger growth on these compounds than on thiamin. Furthermore, oceanic phytoplankton have lower cellular thiamin quotas than previously reported, and salvage of intermediate compounds is likely a key mechanism for meeting B requirements under environmentally relevant scenarios. Thus, several lines of evidence now suggest that availability of specific precursor molecules could be more important in structuring phytoplankton communities than the vitamin itself. This understanding of preferential compound utilization and thiamin quotas will improve biogeochemical model parameterization and highlights interaction networks among ocean microbes.
Topics: Culture Media; Genome; Haptophyta; Metabolic Networks and Pathways; Oceans and Seas; Pyrimidines; Seawater; Thiamine; Transcriptome
PubMed: 29018119
DOI: 10.1128/mBio.01459-17 -
Clinical Cancer Research : An Official... Jul 2016
Topics: Adenine; Humans; Integrin alpha4beta1; Leukemia, Lymphocytic, Chronic, B-Cell; Piperidines; Pyrazoles; Pyrimidines
PubMed: 27371632
DOI: 10.1158/1078-0432.CCR-16-0605 -
Scientific Reports Oct 2019Protein and solid-state nanopores are used for DNA/RNA sequencing as well as for single molecule analysis. We proposed that selective labeling/tagging may improve...
Protein and solid-state nanopores are used for DNA/RNA sequencing as well as for single molecule analysis. We proposed that selective labeling/tagging may improve base-to-base resolution of nucleic acids via nanopores. We have explored one specific tag, the Osmium tetroxide 2,2'-bipyridine (OsBp), which conjugates to pyrimidines and leaves purines intact. Earlier reports using OsBp-tagged oligodeoxyribonucleotides demonstrated proof-of-principle during unassisted voltage-driven translocation via either alpha-Hemolysin or a solid-state nanopore. Here we extend this work to RNA oligos and a third nanopore by employing the MinION, a commercially available device from Oxford Nanopore Technologies (ONT). Conductance measurements demonstrate that the MinION visibly discriminates oligoriboadenylates with sequence APyA, where Py is an OsBp-tagged pyrimidine. Such resolution rivals traditional chromatography, suggesting that nanopore devices could be exploited for the characterization of RNA oligos and microRNAs enhanced by selective labeling. The data also reveal marked discrimination between a single pyrimidine and two consecutive pyrimidines in OsBp-tagged APyA and APyPyA. This observation leads to the conjecture that the MinION/OsBp platform senses a 2-nucleotide sequence, in contrast to the reported 5-nucleotide sequence with native nucleic acids. Such improvement in sensing, enabled by the presence of OsBp, may enhance base-calling accuracy in enzyme-assisted DNA/RNA sequencing.
Topics: 2,2'-Dipyridyl; DNA Fingerprinting; MicroRNAs; Nanopores; Oligoribonucleotides; Organometallic Compounds; Pyrimidines
PubMed: 31578367
DOI: 10.1038/s41598-019-50459-8 -
Scientific Reports Jun 2020RNA viruses are responsible for a large variety of animal infections. Equine Arteritis Virus (EAV) is a positive single-stranded RNA virus member of the family...
RNA viruses are responsible for a large variety of animal infections. Equine Arteritis Virus (EAV) is a positive single-stranded RNA virus member of the family Arteriviridae from the order Nidovirales like the Coronaviridae. EAV causes respiratory and reproductive diseases in equids. Although two vaccines are available, the vaccination coverage of the equine population is largely insufficient to prevent new EAV outbreaks around the world. In this study, we present a high-throughput in vitro assay suitable for testing candidate antiviral molecules on equine dermal cells infected by EAV. Using this assay, we identified three molecules that impair EAV infection in equine cells: the broad-spectrum antiviral and nucleoside analog ribavirin, and two compounds previously described as inhibitors of dihydroorotate dehydrogenase (DHODH), the fourth enzyme of the pyrimidine biosynthesis pathway. These molecules effectively suppressed cytopathic effects associated to EAV infection, and strongly inhibited viral replication and production of infectious particles. Since ribavirin is already approved in human and small animal, and that several DHODH inhibitors are in advanced clinical trials, our results open new perspectives for the management of EAV outbreaks.
Topics: Animals; Antiviral Agents; Arterivirus Infections; Cell Line; Cytopathogenic Effect, Viral; Dihydroorotate Dehydrogenase; Equartevirus; Horse Diseases; Horses; Oxidoreductases Acting on CH-CH Group Donors; Purines; Pyrimidines; RNA; Ribavirin; Virus Replication
PubMed: 32572069
DOI: 10.1038/s41598-020-66944-4 -
Scientific Reports May 2020Enterovirus A71 (EV-A71) is one of the aetiological agents for the hand, foot and mouth disease (HFMD) in young children and a potential cause of neurological...
Enterovirus A71 (EV-A71) is one of the aetiological agents for the hand, foot and mouth disease (HFMD) in young children and a potential cause of neurological complications in afflicted patients. Since its discovery in 1969, there remains no approved antiviral for EV-A71 and other HFMD-causing enteroviruses. We set out to address the lack of therapeutics against EV-A71 by screening an FDA-approved drug library and found an enrichment of hits including pyrimidine antimetabolite, gemcitabine which showed 90.2% of inhibition on EV-A71 infection. Gemcitabine and other nucleoside analogs, LY2334737 and sofosbuvir inhibition of EV-A71 infection were disclosed using molecular and proteomic quantification, and in vitro and in vivo efficacy evaluation. Gemcitabine displayed a significant reduction of infectious EV-A71 titres by 2.5 logs PFU/mL and was shown to target the early stage of EV-A71 viral RNA and viral protein synthesis process especially via inhibition of the RNA dependent RNA polymerase. In addition, the drug combination study of gemcitabine's synergistic effects with interferon-β at 1:1 and 1:2 ratio enhanced inhibition against EV-A71 replication. Since gemcitabine is known to metabolize rapidly in vivo, other nucleoside analogs, LY2334737 and sofosbuvir conferred protection in mice against lethal EV-A71 challenge by potentially reducing the death rate, viral titers as well on virus-induced pathology in the limb muscle tissue of mice. Additionally, we found that gemcitabine is competent to inhibit other positive-sense RNA viruses of the Flaviviridae and Togaviridae family. Overall, these drugs provide new insights into targeting viral factors as a broad-spectrum antiviral strategy with potential therapeutic value for future development and are worthy of potential clinical application.
Topics: Animals; Antiviral Agents; Deoxycytidine; Drug Repositioning; Enterovirus A, Human; Enterovirus Infections; Humans; Mice; Mice, Inbred BALB C; Pyrimidines; RNA, Viral; Virus Replication; Gemcitabine
PubMed: 32424333
DOI: 10.1038/s41598-020-65152-4 -
Environmental Health Perspectives Sep 1994A variety of alkylating mutagens and carcinogens produce pyrimidine adducts in DNA that block DNA synthesis in vitro. Since DNA synthesis past the lesion is a necessary... (Review)
Review
A variety of alkylating mutagens and carcinogens produce pyrimidine adducts in DNA that block DNA synthesis in vitro. Since DNA synthesis past the lesion is a necessary step to produce mutations, we investigated the role of the mutagenic metal ion Mn++ in facilitating DNA synthesis past alkylpyrimidines. In the presence of the natural metal activator Mg++, N3-ethyldeoxythymidine (N3-Et-dT) and O2-ethyldeoxythymidine (O2-Et-dT), present at a single site in DNA, blocked in vitro DNA synthesis 3' to the lesion and after incorporating dA opposite each lesion. The presence of Mn++ permitted postlesion synthesis with dT misincorporated opposite N3-Et-dT and O2-Et-dT, implicating these lesions in A.T-->T.A transversion mutagenesis. The DNA synthesis block by O4-ethyldeoxythymidine (O4-Et-dT) in the presence of Mg++ was partial and was also removed by Mn++. Consistent with in vivo studies, dG was incorporated opposite O4-Et-dT during postlesion synthesis, leading to A.T-->G.C transition mutagenesis. We also have discovered a new class of DNA adducts, N3-hydroxyalkyldeoxyuridine (3-HA-dU) lesions, which are produced by mutagenic and carcinogenic aliphatic epoxides. 3-HA-dU is formed after initial alkylation at the N3 position of dC followed by a rapid hydrolytic deamination. As observed with the analogous mutagenic N3-Et-dT, the ethylene oxide-induced 3-hydroxyethyldeoxyuridine (3-HE-dU) blocked in vitro DNA synthesis, which could be by-passed in the presence of Mn++. The nucleotide incorporated opposite 3-HE-dU during postlesion synthesis is being identified. These studies suggest a role for Mn++ in mediating mutagenic and carcinogenic effects of environmentally important ethylating agents and aliphatic epoxides.
Topics: Alkylation; Animals; Base Composition; Base Sequence; DNA Replication; Manganese Poisoning; Metals; Molecular Sequence Data; Mutagens; Pyrimidines
PubMed: 7843141
DOI: 10.1289/ehp.94102s381