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Molecules (Basel, Switzerland) May 2024A versatile family of quaternary propargylamines was synthesized employing the KA multicomponent reaction, through the single-step coupling of a number of amines,...
A versatile family of quaternary propargylamines was synthesized employing the KA multicomponent reaction, through the single-step coupling of a number of amines, ketones, and terminal alkynes. Sustainable synthetic procedures using transition metal catalysts were employed in all cases. The inhibitory activity of these molecules was evaluated against human monoaminoxidase (hMAO)-A and hMAO-B enzymes and was found to be significant. The IC values for hMAO-B range from 152.1 to 164.7 nM while the IC values for hMAO-A range from 765.6 to 861.6 nM. Furthermore, these compounds comply with Lipinski's rule of five and exhibit no predicted toxicity. To understand their binding properties with the two target enzymes, key interactions were studied using molecular docking, all-atom molecular dynamics (MD) simulations, and MM/GBSA binding free energy calculations. Overall, herein, the reported family of propargylamines exhibits promise as potential treatments for neurodegenerative disorders, such as Parkinson's disease. Interestingly, this is the first time a propargylamine scaffold bearing an internal alkyne has been reported to show activity against monoaminoxidases.
Topics: Alkynes; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Pargyline; Propylamines; Structure-Activity Relationship; Molecular Structure
PubMed: 38893361
DOI: 10.3390/molecules29112486 -
Brain Communications 2024Dravet syndrome is a severe genetic epilepsy primarily caused by mutations in a voltage-activated sodium channel gene (). Patients face life-threatening seizures that...
Dravet syndrome is a severe genetic epilepsy primarily caused by mutations in a voltage-activated sodium channel gene (). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications. Preclinical Dravet syndrome animal models are a valuable tool to identify candidate anti-seizure medications for these patients. Among these, mutant zebrafish, exhibiting spontaneous seizure-like activity, are particularly amenable to large-scale drug screening. Thus far, we have screened more than 3000 drug candidates in zebrafish mutants, identifying valproate, stiripentol, and fenfluramine e.g. Food and Drug Administration-approved drugs, with clinical application in the Dravet syndrome population. Successful phenotypic screening in mutant zebrafish is rigorous and consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behaviour and (ii) an electrophysiology-based assay, using local field potential recordings, to quantify electrographic seizure-like events. Historically, nearly 90% of drug candidates fail during translation from preclinical models to the clinic. With such a high failure rate, it becomes necessary to address issues of replication and false positive identification. Leveraging our zebrafish assays is one approach to address these problems. Here, we curated a list of nine anti-seizure drug candidates recently identified by other groups using preclinical Dravet syndrome models: 1-Ethyl-2-benzimidazolinone, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in mutant zebrafish identified only 1-Ethyl-2-benzimidazolinone, chlorzoxazone and lisuride. However, second-stage local field potential recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of anti-seizure medications.
PubMed: 38707709
DOI: 10.1093/braincomms/fcae135 -
Molecular Neurodegeneration Apr 2024Hypometabolism tied to mitochondrial dysfunction occurs in the aging brain and in neurodegenerative disorders, including in Alzheimer's disease, in Down syndrome, and in...
BACKGROUND
Hypometabolism tied to mitochondrial dysfunction occurs in the aging brain and in neurodegenerative disorders, including in Alzheimer's disease, in Down syndrome, and in mouse models of these conditions. We have previously shown that mitovesicles, small extracellular vesicles (EVs) of mitochondrial origin, are altered in content and abundance in multiple brain conditions characterized by mitochondrial dysfunction. However, given their recent discovery, it is yet to be explored what mitovesicles regulate and modify, both under physiological conditions and in the diseased brain. In this study, we investigated the effects of mitovesicles on synaptic function, and the molecular players involved.
METHODS
Hippocampal slices from wild-type mice were perfused with the three known types of EVs, mitovesicles, microvesicles, or exosomes, isolated from the brain of a mouse model of Down syndrome or of a diploid control and long-term potentiation (LTP) recorded. The role of the monoamine oxidases type B (MAO-B) and type A (MAO-A) in mitovesicle-driven LTP impairments was addressed by treatment of mitovesicles with the irreversible MAO inhibitors pargyline and clorgiline prior to perfusion of the hippocampal slices.
RESULTS
Mitovesicles from the brain of the Down syndrome model reduced LTP within minutes of mitovesicle addition. Mitovesicles isolated from control brains did not trigger electrophysiological effects, nor did other types of brain EVs (microvesicles and exosomes) from any genotype tested. Depleting mitovesicles of their MAO-B, but not MAO-A, activity eliminated their ability to alter LTP.
CONCLUSIONS
Mitovesicle impairment of LTP is a previously undescribed paracrine-like mechanism by which EVs modulate synaptic activity, demonstrating that mitovesicles are active participants in the propagation of cellular and functional homeostatic changes in the context of neurodegenerative disorders.
Topics: Humans; Animals; Mice; Extracellular Space; Down Syndrome; Neuronal Plasticity; Brain; Alzheimer Disease; Disease Models, Animal; Monoamine Oxidase; Mitochondrial Diseases
PubMed: 38616258
DOI: 10.1186/s13024-024-00721-z -
Journal of Chromatography. B,... May 2024Trace amines are powerful neuromodulators influencing the release and reuptake of catecholamines. These low concentrated endogenous amines impact mood, cognition, and...
OBJECTIVES
Trace amines are powerful neuromodulators influencing the release and reuptake of catecholamines. These low concentrated endogenous amines impact mood, cognition, and hormone regulation. Dysregulation of trace amines have been associated with a variety of diseases, such as schizophrenia, Parkinson's disease, migraine, depression and more. Succesfull simultaneous quantification of trace amines, their precursors and metabolites would benefit both research and patient care. Since these compounds have various functional groups and are present in biological matrices with large concentration difference, their simultaneous quantification is an analytical challenge. Our goal was to develop a highly sensitive LC-MS/MS assay to simultaneously quantify trace amines, their precursors and metabolites in plasma.
METHODS
Our method is based on a simple two-step in-matrix derivatization protocol: propionic anhydride (PA) and 3-Ethyl-1-[3-(dimethylamino)propyl]carbodiimide (EDC) in combination with 2,2,2-trifluoroethylamine (TFEA) followed by online solid phase extraction combined with LC-MS/MS. Fifteen metabolites can be measured simultaneously, three precursors, eight trace amines and four metabolites. Validation of this method was performed according to international validation guidelines. The pre-analytical stability of trace amines was assessed.
RESULTS
This novel method was successful in quantifying trace amines, their precursors, and metabolites in plasma. Using just 50 µl human plasma, we were able to accomplish limit of quantification for 2-phenylethylamine and N-methyl-phenylethylamine of 0.2 nmol/L and 0.1 nmol/L for tyramine and n-methyltyramine. Inter-and intra-assay imprecision was < 15 % for all analytes. Stability assessment showed susceptibility of certain trace amines e.g. 2-phenylethylamine and N-methyl-phenylethylamine to enzymatic degradation in plasma. The addition of the monoamine oxidase inhibitor pargyline to plasma prevented this enzymatic degradation.
CONCLUSIONS
We developed a novel LC-MS/MS method that1) uses a new double derivatization technique, 2) is automated with online SPE, 3) uses far less sample volume then previous methods and 4) detects more components in the same sample (eight trace amines, three precursors, and four metabolites) with high specificity and selectivity. Furthermore, addition of MAO A/B inhibitor prevents degradation and guarantees more accurate quantification of trace amines.
Topics: Humans; Tandem Mass Spectrometry; Reproducibility of Results; Amines; Chromatography, Liquid; Limit of Detection; Linear Models; Solid Phase Extraction
PubMed: 38583227
DOI: 10.1016/j.jchromb.2024.124098 -
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 -
Biomaterials Advances May 2024Although several bioactive 3D-printed bone scaffolds loaded with multiple kinds of biomolecules for enhanced bone regeneration have been recently developed, the...
Although several bioactive 3D-printed bone scaffolds loaded with multiple kinds of biomolecules for enhanced bone regeneration have been recently developed, the manipulation of on-demand release profiles of different biomolecules during bone regeneration remains challenging. Herein, a 3D-printed dual-drug-loaded biomimetic scaffold to regulate the host stem cell recruitment and osteogenic differentiation in a two-stage process for bone regeneration was successfully fabricated. First, a chemotactic small-molecule drug, namely, simvastatin (SIM) was directly incorporated into the hydroxyapatite/collagen bioink for printing and could be rapidly released during the early stage of bone regeneration. Further, near-infrared (NIR)-light-responsive polydopamine-coated hydroxyapatite nanoparticles were designed to deliver the osteogenic drug, i.e., pargyline (PGL) in a controllable manner. Together, our scaffold displayed an on-demand sequential release of those two drugs and could optimize their therapeutic effects to align with the stem cell recruitment and osteoblastic differentiation, thereby promoting bone regeneration. The results confirmed the suitable mechanical strength, high photothermal conversion efficiency, good biocompatibility of our scaffold. The scaffold loaded with SIM could efficiently accelerate the migration of stem cells. In addition, the scaffold with on-demand sequential release promoted alkaline phosphatase (ALP) activity, significantly upregulated gene expression levels of osteogenesis-related markers, and enhanced new-bone-formation capabilities in rabbit cranial defect models. Altogether, this scaffold not only offers a promising strategy to control the behavior of stem cells during bone regeneration but also provides an efficient strategy for controllable sequential release of different biomolecule in bone tissue engineering.
Topics: Animals; Rabbits; Osteogenesis; Tissue Scaffolds; Bone Regeneration; Durapatite; Printing, Three-Dimensional
PubMed: 38412627
DOI: 10.1016/j.bioadv.2024.213804 -
Biomacromolecules Feb 2024Both biochemical and mechanical cues could regulate the function of stem cells, but the interaction mechanism of their signaling pathway remains unclear, especially in...
Both biochemical and mechanical cues could regulate the function of stem cells, but the interaction mechanism of their signaling pathway remains unclear, especially in the three-dimensional (3D) culture mode. Higher matrix stiffness promotes osteogenic differentiation of stem cells, and bone morphogenic protein-2 (BMP-2) has been clinically applied to promote bone regeneration. Here, the crosstalk of extracellular mechanical signals on BMP-2 signaling was investigated in rat bone marrow stromal cells (rMSCs) cultured inside cryogels with interconnective pores. Stiff cryogel independently promoted osteogenic differentiation and enhanced the autocrine secretion of BMP-2, thus stimulating increased phosphorylation levels of the Smad1/5/8 complex. BMP-2 mimetic peptide (BMMP) and high cryogel stiffness jointly guided the osteogenic differentiation of rMSCs. Inhibition of rho-associated kinase (ROCK) by Y-27632 or inhibition of nonmuscle myosin II (NM II) by blebbistatin showed that osteogenesis induction by BMP-2 signaling, as well as autocrine secretion of BMP-2 and phosphorylation of the Smad complex, requires the involvement of cytoskeletal tension and ROCK pathway signaling. An interconnective microporous cryogel scaffold promoted rMSC osteogenic differentiation by combining matrix stiffness and BMMP, and it accelerated critical cranial defect repair in the rat model.
Topics: Rats; Animals; Osteogenesis; Cryogels; Gelatin; Cell Differentiation; Mesenchymal Stem Cells; Bone Morphogenetic Protein 2; Bone Marrow Cells; Cells, Cultured; Pargyline
PubMed: 38180887
DOI: 10.1021/acs.biomac.3c01045 -
BioRxiv : the Preprint Server For... Nov 2023Dravet syndrome (DS) is a severe genetic epilepsy primarily caused by mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening...
Dravet syndrome (DS) is a severe genetic epilepsy primarily caused by mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications (ASM). Preclinical DS animal models are a valuable tool to identify candidate ASMs for these patients. Among these, mutant zebrafish exhibiting spontaneous seizure-like activity are particularly amenable to large-scale drug screening. Prior screening in a mutant zebrafish line generated using N-ethyl-Nnitrosourea (ENU) identified valproate, stiripentol, and fenfluramine e.g., Federal Drug Administration (FDA) approved drugs with clinical application in the DS population. Successful phenotypic screening in mutant zebrafish consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behavior and (ii) an electrophysiology-based assay, using local field potential (LFP) recordings, to quantify electrographic seizure-like events. Using this strategy more than 3000 drug candidates have been screened in zebrafish mutants. Here, we curated a list of nine additional anti-seizure drug candidates recently identified in preclinical models: 1-EBIO, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in mutant zebrafish identified only 1-EBIO, chlorzoxazone and lisuride. However, second-stage LFP recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of ASMs.
PubMed: 38014342
DOI: 10.1101/2023.11.11.566723 -
Molecules (Basel, Switzerland) Aug 2023Monoamine oxidase (MAO, EC 1.4.3.4) is responsible for the oxidative breakdown of both endogenous and exogenous amines and exists in MAO-A and MAO-B isomers. Eighteen...
Assembling a Cinnamyl Pharmacophore in the C3-Position of Substituted Isatins via Microwave-Assisted Synthesis: Development of a New Class of Monoamine Oxidase-B Inhibitors for the Treatment of Parkinson's Disease.
Monoamine oxidase (MAO, EC 1.4.3.4) is responsible for the oxidative breakdown of both endogenous and exogenous amines and exists in MAO-A and MAO-B isomers. Eighteen indole-based phenylallylidene derivatives were synthesized via nucleophilic addition reactions comprising three sub-series, , , and , and were developed and examined for their ability to inhibit MAO. Among them, compound showed a strong MAO-B inhibitory effect with an IC () value of 1.672 μM, followed by (IC = 16.934 μM). Additionally, showed the highest selectivity index (SI) value of >23.92. The effectiveness of was lower than the reference pargyline (0.14 μM); however, the SI value was higher than pargyline (17.16). Structurally, the (-H in the B-ring) sub-series exhibited relatively stronger MAO-B inhibition than the others. In the series, (-F in the A-ring) exhibited stronger MAO-B suppression than the other substituted derivatives in the order -F > -Br > -Cl > -OCH, -CH, and -H at the 2-position in the A-ring. In the reversibility and enzyme kinetics experiments, was a reversible inhibitor with a K value of 0.51 ± 0.15 μM for MAO-B. Further, it was observed that greatly decreased the cell death caused by rotenone in SH-SY5Y neuroblastoma cells. A molecular docking study of the lead molecule was also performed to determine hypothetical interactions in the enzyme-binding cavity. These findings suggest that is a strong, specific, and reversible MAO-B inhibitor that can be used to treat neurological diseases.
Topics: Humans; Parkinson Disease; Isatin; Microwaves; Molecular Docking Simulation; Pargyline; Pharmacophore; Neuroblastoma; Dopamine Agents; Monoamine Oxidase; Antipsychotic Agents
PubMed: 37630420
DOI: 10.3390/molecules28166167 -
Chemical Biology & Drug Design Aug 2023Eight derivatives of benzyloxy-derived halogenated chalcones (BB1-BB8) were synthesized and tested for their ability to inhibit monoamine oxidases (MAOs). MAO-A was less...
Eight derivatives of benzyloxy-derived halogenated chalcones (BB1-BB8) were synthesized and tested for their ability to inhibit monoamine oxidases (MAOs). MAO-A was less efficiently inhibited by all compounds than MAO-B. Additionally, the majority of the compounds displayed significant MAO-B inhibitory activities at 1 μM with residual activities of less than 50%. With an IC value of 0.062 μM, compound BB4 was the most effective in inhibiting MAO-B, followed by compound BB2 (IC = 0.093 μM). The lead molecules showed good activity than the reference MAO-B inhibitors (Lazabemide IC = 0.11 μM and Pargyline Pargyline IC = 0.14). The high selectivity index (SI) values for MAO-B were observed in compounds BB2 and BB4 (430.108 and 645.161, respectively). Kinetics and reversibility experiments revealed that BB2 and BB4 were reversible competitive MAO-B inhibitors with K values of 0.030 ± 0.014 and 0.011 ± 0.005 μM, respectively. Swiss target prediction confirmed the high probability in the targets of MAO-B for both compounds. Hypothetical binding mode revealed that the BB2 or BB4 is similarly oriented to the binding cavity of MAO-B. Based on the modelling results, BB4 showed a stable confirmation during the dynamic simulation. From these results, it was concluded that BB2 and BB4 were potent selective reversible MAO-B inhibitors and they can be considered drug candidates for treating related neurodegenerative diseases such as Parkinson's disease.
Topics: Monoamine Oxidase Inhibitors; Chalcones; Structure-Activity Relationship; Pargyline; Pharmacophore; Molecular Docking Simulation; Monoamine Oxidase
PubMed: 37011915
DOI: 10.1111/cbdd.14238