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Neurochemistry International May 2021Monoamine oxidase (MAO) enzymes, type A and B metabolise the amine neurotransmitters of the body. Selective inhibition of either enzyme is an approach for treating...
Monoamine oxidase (MAO) enzymes, type A and B metabolise the amine neurotransmitters of the body. Selective inhibition of either enzyme is an approach for treating neurodegenerative and stress-induced disorders, and inhibition of an enzyme is proportional to the binding of the MAO inhibitor. Conventionally, the binding of test compounds to enzymes is assessed by radiolabelled ligands in ex vivo and in vivo occupancy assays. Regulatory restrictions and turnaround time are the limitations of the methods that use radiolabelled ligands. But the use of non-radiolabelled tracers and sensitive mass spectrometry (LC-MS/MS) based assays accelerated the determination of target occupancy in pre-clinical species. A report on use of non-radiolabelled ligand in in vivo MAO occupancy assay is not available. The objectives of the present study were to optimise non-radiolabelled harmine and deprenyl as selective tracers in MAO-A and MAO-B occupancy assays and evaluate MAO occupancy of test compounds in rat brain. Tracer optimisation resulted in a detectable, stable, and low ratio (<3.0) of tracer concentrations between any two brain tissues. In occupancy assay, tracer was intravenously administered (10 μg/kg, harmine or 60 μg/kg, L-deprenyl) after the treatment with test compound (clorgyline or tranylcypromine or pargyline or phenelzine or thioperamide). Specific brain tissues were isolated at a defined interval and tracer concentrations were quantified using LC-MS/MS method. Pre-treatment with MAO inhibitors resulted in a decrease (maximum, 80-85%) in harmine or an increase (maximum, 85-300%) in L-deprenyl concentrations. But we considered the change in tracer concentration, relative to the vehicle and positive control groups to calculate MAO occupancy. The observed selectivity and ratio of occupancies (ED) of test compound towards MAO-A and MAO-B are comparable with the results from in vitro radiolabelled ligand-based inhibition assay. The results demonstrated the application of these non-radiolabelled tracers as suitable pre-clinical tools to determine MAO occupancy.
Topics: Administration, Intravenous; Animals; Brain; Dose-Response Relationship, Drug; Harmine; Male; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Protein Binding; Rats; Rats, Sprague-Dawley; Selegiline
PubMed: 33636211
DOI: 10.1016/j.neuint.2021.105006 -
Cell Death & Disease Sep 2019The C-terminal binding protein (CtBP) is an NADH-dependent dimeric family of nuclear proteins that scaffold interactions between transcriptional regulators and...
The C-terminal binding protein (CtBP) is an NADH-dependent dimeric family of nuclear proteins that scaffold interactions between transcriptional regulators and chromatin-modifying complexes. Its association with poor survival in several cancers implicates CtBP as a promising target for pharmacological intervention. We employed computer-assisted drug design to search for CtBP inhibitors, using quantitative structure-activity relationship (QSAR) modeling and docking. Functional screening of these drugs identified 4 compounds with low toxicity and high water solubility. Micro molar concentrations of these CtBP inhibitors produces significant de-repression of epigenetically silenced pro-epithelial genes, preferentially in the triple-negative breast cancer cell line MDA-MB-231. This epigenetic reprogramming occurs through eviction of CtBP from gene promoters; disrupted recruitment of chromatin-modifying protein complexes containing LSD1, and HDAC1; and re-wiring of activating histone marks at targeted genes. In functional assays, CtBP inhibition disrupts CtBP dimerization, decreases cell migration, abolishes cellular invasion, and improves DNA repair. Combinatorial use of CtBP inhibitors with the LSD1 inhibitor pargyline has synergistic influence. Finally, integrated correlation of gene expression in breast cancer patients with nuclear levels of CtBP1 and LSD1, reveals new potential therapeutic vulnerabilities. These findings implicate a broad role for this class of compounds in strategies for epigenetically targeted therapeutic intervention.
Topics: Alcohol Oxidoreductases; Breast Neoplasms; DNA-Binding Proteins; Epigenesis, Genetic; Female; Humans
PubMed: 31534138
DOI: 10.1038/s41419-019-1892-7 -
Organic Letters Jul 2021We report here a three-component, Cu(I)-catalyzed hexadehydro-Diels-Alder (HDDA) benzyne 1,2-difunctionalization reaction. This protocol allowed the introduction of two...
We report here a three-component, Cu(I)-catalyzed hexadehydro-Diels-Alder (HDDA) benzyne 1,2-difunctionalization reaction. This protocol allowed the introduction of two different carbon-based substituents onto the in situ-generated benzyne. These substituents were terminal monoynes or diynes partnered with propargylic, benzylic, or allylic chlorides. An example of a sequential HDDA reaction is demonstrated using the product of a 1,3-diyne and a propargylic halide, itself a newly created HDDA precursor.
Topics: Benzene Derivatives; Catalysis; Copper; Cycloaddition Reaction; Diynes; Molecular Structure; Pargyline
PubMed: 34180676
DOI: 10.1021/acs.orglett.1c01788 -
Journal of Medicinal Chemistry Feb 2022Glioma treatment remains a challenge with a low survival rate due to the lack of effective therapeutics. Monoamine oxidase A (MAO A) plays a role in glioma development,...
Glioma treatment remains a challenge with a low survival rate due to the lack of effective therapeutics. Monoamine oxidase A (MAO A) plays a role in glioma development, and MAO A inhibitors reduce glioma growth. Histone deacetylase (HDAC) inhibition has emerged as a promising therapy for various malignancies including gliomas. We have synthesized and evaluated -methylpropargylamine-conjugated hydroxamic acids as dual inhibitors of MAO A and HDAC. Compounds display potent MAO A inhibition with IC from 0.03 to <0.0001 μM and inhibit HDAC isoforms and cell growth in the micromolar to nanomolar IC range. These selective MAO A inhibitors increase histone H3 and α-tubulin acetylation and induce cell death via nonapoptotic mechanisms. Treatment with reduced tumor size, reduced MAO A activity in brain and tumor tissues, and prolonged the survival. This first report on dual inhibitors of MAO A and HDAC establishes the basis of translational research for an improved treatment of glioma.
Topics: Acetylation; Animals; Cell Line, Tumor; Cell Proliferation; Drug Design; Enzyme Inhibitors; Glioma; Histone Deacetylases; Histones; Humans; Hydroxamic Acids; Isoenzymes; Kaplan-Meier Estimate; Male; Mice; Mice, Inbred C57BL; Monoamine Oxidase; Pargyline; Propylamines; Structure-Activity Relationship; Transplantation, Heterologous
PubMed: 35005974
DOI: 10.1021/acs.jmedchem.1c01726 -
Dalton Transactions (Cambridge, England... Mar 2024Three pargyline-phosphine copper(I) clusters, [Cu(CC-CHN)(PPh)](PF) (1) and [Cu(CC-CHN)(dppy)](X) (dppy = diphenyl-2-pyridylphosphine; X = PF for 2 and X = ClO for...
Three pargyline-phosphine copper(I) clusters, [Cu(CC-CHN)(PPh)](PF) (1) and [Cu(CC-CHN)(dppy)](X) (dppy = diphenyl-2-pyridylphosphine; X = PF for 2 and X = ClO for 3), were synthesized. Their structures were fully characterized using various spectroscopic methods and X-ray crystallography, which showed that the stoichiometry and nature of pargyline and phosphine ligands play an important role in tuning the structure and photophysical features of Cu(I) clusters. Interestingly, clusters 1, 2 and 3 exhibited red, orange and yellow phosphorescence with high quantum yields of 88.5%, 22.0% and 40.2%, respectively, at room temperature. Moreover, clusters 1-3 show distinct temperature-dependent emissions. The excellent luminescence performance of 1 and 3 was designed and employed for the construction of monochrome and white light-emitting devices (LEDs).
PubMed: 38469690
DOI: 10.1039/d4dt00022f -
Bioorganic & Medicinal Chemistry Letters Aug 2021Twenty six propargylamine mycophenolate analogues were designed and synthesized from mycophenolic acid 1 employing a key step A-coupling reaction. Their cytotoxic...
Twenty six propargylamine mycophenolate analogues were designed and synthesized from mycophenolic acid 1 employing a key step A-coupling reaction. Their cytotoxic activity was examined against six cancer cell lines. Compounds 6a, 6j, 6t, 6u, and 6z exhibited selective cytotoxicity towards neuroblastoma (SH-SY5Y) cancer cells and were less toxic to normal cells in comparison to the lead compound, MPA 1 and a standard drug, ellipticine. Molecular docking results suggested that compound 6a is fit well in the key amino acid of three proteins (CDK9, EGFR, and VEGFR-2) as targets in cancer therapy. The propargylamine mycophenolate scaffold might be a valuable starting point for development of new neuroblastoma anticancer drugs.
Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Molecular Docking Simulation; Molecular Structure; Mycophenolic Acid; Neuroblastoma; Pargyline; Propylamines; Structure-Activity Relationship
PubMed: 34044119
DOI: 10.1016/j.bmcl.2021.128135 -
Frontiers in Pharmacology 2021Monoamine oxidases (MAO) are a valuable class of mitochondrial enzymes with a critical role in neuromodulation. In this study, we investigated the effect of natural MAO...
Monoamine oxidases (MAO) are a valuable class of mitochondrial enzymes with a critical role in neuromodulation. In this study, we investigated the effect of natural MAO inhibitors on novel environment-induced anxiety by using the zebrafish novel tank test (NTT). Because zebrafish spend more time at the bottom of the tank when they are anxious, anxiolytic compounds increase the time zebrafish spend at the top of the tank and vice versa. Using this paradigm, we found that harmane, norharmane, and 1,2,3,4-tetrahydroisoquinoline (TIQ) induce anxiolytic-like effects in zebrafish, causing them to spend more time at the top of the test tank and less time at the bottom. 2,3,6-trimethyl-1,4-naphtoquinone (TMN) induced an interesting mix of both anxiolytic- and anxiogenic-like effects during the first and second halves of the test, respectively. TIQ was unique in having no observable effect on general movement. Similarly, a reference MAO inhibitor clorgyline-but not pargyline-increased the time spent at the top in a concentration-dependent manner. We also demonstrated that the brain bioavailability of these compounds are high based on the bioavailability assay and in silico prediction models, which support the notion that the observed effects on anxiety-like behavior in zebrafish were most likely due to the direct effect of these compounds in the brain. This study is the first investigation to demonstrate the anxiolytic-like effects of MAO inhibitors on novel environment-induced anxiety in zebrafish.
PubMed: 34079463
DOI: 10.3389/fphar.2021.669370 -
Environmental Science and Pollution... Feb 2021Urban particulate matter (PM), a great danger to public health, is associated with increasing risk of pulmonary diseases. However, the involved key genes and signaling...
Urban particulate matter (PM), a great danger to public health, is associated with increasing risk of pulmonary diseases. However, the involved key genes and signaling pathways mediating the cellular responses to urban PM are largely unknown. In this study, human bronchial epithelial cells BEAS-2B was exposed to Standard reference material (SRM) 1649b, followed by RNA-sequencing (RNA-seq) and a combination of different bioinformatics analysis. A total of 201 genes (111 upregulated and 90 downregulated) were identified as the differentially expressed genes (DEGs). Moreover, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) unveiled several significant genes and pathways involved in PM-induced lung toxicity. Protein-protein interaction (PPI) network was performed with the Search Tool for the Retrieval of Interacting Genes (STRING), and the hub gene modules were recognized by Molecular Complex Detection (MCODE), a plug-in of Cytoscape. Moreover, Connectivity Map (CMap) analysis found six candidate small molecular compounds to reverse PM-altered gene expression, including aminohippuric acid, captopril, cinoxacin, fasudil, pargyline, and altizide. Finally, the expressions of part vital genes related to inflammation (IL-1β, CXCL2, CXCL5, CXCL8), ferroptosis (HMOX1, GCLM), and autophagy (BECN1, MAPK1LC3B) were in accordance with the RNA-seq data, with a concentration-dependent manner. This study may be helpful in revealing the complex molecular mechanisms underlying PM-induced lung toxicity and provide some new therapeutic targets for PM-related pulmonary diseases.
Topics: Epithelial Cells; Gene Expression Profiling; Gene Ontology; Humans; Particulate Matter; Transcriptome
PubMed: 33150508
DOI: 10.1007/s11356-020-11347-1 -
Carbohydrate Research Oct 2019This work combined three classes of compounds in the same molecule "amino triazole-glycoside" and developed a convenient method for the synthesis of this type of...
This work combined three classes of compounds in the same molecule "amino triazole-glycoside" and developed a convenient method for the synthesis of this type of compound via a one-pot two step reaction. Alkylation of amine derivatives with propargyl bromide to give propargylamine was performed in the first step subsequently followed by a 'click' reaction with various β-azido-glycosides in the presence of CuI in aqueous solution to provide β-amino triazole-glycosides. Thirty-two examples of glycosides were obtained in moderate to good yield using this one-pot procedure.
Topics: Alkylation; Amines; Carbohydrate Sequence; Click Chemistry; Glycosides; Pargyline; Propylamines; Triazoles
PubMed: 31479870
DOI: 10.1016/j.carres.2019.107780 -
ACS Chemical Biology Sep 2021Ubiquitin activity-based probes have proven invaluable in elucidating structural mechanisms in the ubiquitin system by stabilizing transient macromolecular complexes of...
Ubiquitin activity-based probes have proven invaluable in elucidating structural mechanisms in the ubiquitin system by stabilizing transient macromolecular complexes of deubiquitinases, ubiquitin-activating enzymes, and the assemblies of ubiquitin-conjugating enzymes with ubiquitin ligases of the RING-Between-RING and RING-Cysteine-Relay families. Here, we demonstrate that an activity-based probe, ubiquitin-propargylamine, allows for the preparative reconstitution and structural analysis of the interactions between ubiquitin and certain HECT ligases. We present a crystal structure of the ubiquitin-linked HECT domain of HUWE1 that defines a catalytically critical conformation of the C-terminal tail of the ligase for the transfer of ubiquitin to an acceptor protein. Moreover, we observe that ubiquitin-propargylamine displays selectivity among HECT domains, thus corroborating the notion that activity-based probes may provide entry points for the development of specific, active site-directed inhibitors and reporters of HECT ligase activities.
Topics: Amino Acid Sequence; Catalysis; Catalytic Domain; Cysteine; Humans; Models, Molecular; Pargyline; Propylamines; Protein Conformation; Structure-Activity Relationship; Substrate Specificity; Ubiquitin; Ubiquitin-Conjugating Enzymes; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 34403242
DOI: 10.1021/acschembio.1c00433