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1.
Molecules ; 25(7)2020 Apr 10.
Article de Anglais | MEDLINE | ID: mdl-32290261

RÉSUMÉ

The human gamma-herpesviruses Epstein-Barr virus (EBV) (HHV-4) and Kaposi's sarcoma-associated herpesvirus (KSHV) (HHV-8) are responsible for a number of diseases, including various types of cancer. Epstein-Barr nuclear antigen 1 (EBNA1) from EBV and latency-associated nuclear antigen (LANA) from KSHV are viral-encoded DNA-binding proteins that are essential for the replication and maintenance of their respective viral genomes during latent, oncogenic infection. As such, EBNA1 and LANA are attractive targets for the development of small-molecule inhibitors. To this end, we performed a biophysical screen of EBNA1 and LANA using a fragment library by saturation transfer difference (STD)-NMR spectroscopy and surface plasmon resonance (SPR). We identified and validated a number of unique fragment hits that bind to EBNA1 or LANA. We also determined the high-resolution crystal structure of one fragment bound to EBNA1. Results from this screening cascade provide new chemical starting points for the further development of potent inhibitors for this class of viral proteins.


Sujet(s)
Antigènes viraux/composition chimique , ADN viral/composition chimique , Protéines de liaison à l'ADN/composition chimique , Découverte de médicament , Antigènes nucléaires du virus d'Epstein-Barr/composition chimique , Protéines nucléaires/composition chimique , Antigènes viraux/métabolisme , ADN viral/métabolisme , Protéines de liaison à l'ADN/métabolisme , Découverte de médicament/méthodes , Antigènes nucléaires du virus d'Epstein-Barr/métabolisme , Gammapapillomavirus , Herpèsvirus humain de type 4 , Herpèsvirus humain de type 8/métabolisme , Humains , Ligands , Spectroscopie par résonance magnétique , Modèles moléculaires , Protéines nucléaires/métabolisme , Bibliothèques de petites molécules , Relation structure-activité
2.
Sci Transl Med ; 11(482)2019 03 06.
Article de Anglais | MEDLINE | ID: mdl-30842315

RÉSUMÉ

Epstein-Barr virus (EBV) is a DNA tumor virus responsible for 1 to 2% of human cancers including subtypes of Burkitt's lymphoma, Hodgkin's lymphoma, gastric carcinoma, and nasopharyngeal carcinoma (NPC). Persistent latent infection drives EBV-associated tumorigenesis. Epstein-Barr nuclear antigen 1 (EBNA1) is the only viral protein consistently expressed in all EBV-associated tumors and is therefore an attractive target for therapeutic intervention. It is a multifunctional DNA binding protein critical for viral replication, genome maintenance, viral gene expression, and host cell survival. Using a fragment-based approach and x-ray crystallography, we identify a 2,3-disubstituted benzoic acid series that selectively inhibits the DNA binding activity of EBNA1. We characterize these inhibitors biochemically and in cell-based assays, including chromatin immunoprecipitation and DNA replication assays. In addition, we demonstrate the potency of EBNA1 inhibitors to suppress tumor growth in several EBV-dependent xenograft models, including patient-derived xenografts for NPC. These inhibitors selectively block EBV gene transcription and alter the cellular transforming growth factor-ß (TGF-ß) signaling pathway in NPC tumor xenografts. These EBNA1-specific inhibitors show favorable pharmacological properties and have the potential to be further developed for the treatment of EBV-associated malignancies.


Sujet(s)
ADN viral/métabolisme , Conception de médicament , Antigènes nucléaires du virus d'Epstein-Barr/métabolisme , Herpèsvirus humain de type 4/physiologie , Tumeurs du rhinopharynx/virologie , Bibliothèques de petites molécules/composition chimique , Bibliothèques de petites molécules/pharmacologie , Latence virale/effets des médicaments et des substances chimiques , Animaux , Prolifération cellulaire/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Régulation de l'expression des gènes viraux/effets des médicaments et des substances chimiques , Humains , Souris nude , Tumeurs du rhinopharynx/anatomopathologie , Relation structure-activité
3.
ACS Med Chem Lett ; 9(7): 752-756, 2018 Jul 12.
Article de Anglais | MEDLINE | ID: mdl-30034613

RÉSUMÉ

We have previously reported a prodrug strategy based on the marketed drug riluzole (2-amino-6-trifluoromethoxybenzothiazole), associated with the benefits of lower patient to patient variability of exposure and potentially once daily oral dosing, as opposed to the large variance and twice daily dosing, which is currently observed with the parent drug. Riluzole is a glutamate modulator that is currently approved by the US FDA to treat amyotrophic lateral sclerosis (ALS). Riluzole also strongly suppresses the growth of melanoma cells that express the type 1 metabotropic glutamate receptor (GRM1, mGluR1). Riluzole is a substrate for the variably expressed liver isozyme CYP1A2, which has been shown to contribute to the variance in exposure of riluzole in humans upon oral administration. In addition, an elevated Cmax following oral administration is a probable cause of increased liver enzyme levels in some patients. In order to mitigate these issues, a series of natural and unnatural dipeptide prodrugs of riluzole were prepared as products that bear lower first-pass hepatic clearance. The prodrugs were evaluated for their ability to produce riluzole in serum while remaining intact prior to absorption from the GI tract, characteristic of a type IIB prodrug. Here, we describe dipeptide conjugates of riluzole and report that the t-Bu-Gly-Sar-riluzole analog FC-3423 (6) is absorbed well and converts to riluzole in rats and mice in a regular and well-defined manner. FC-3423 strongly suppress tumor cell growth in mouse xenograft models of melanoma at a molar dose 10-fold less than that of riluzole itself.

4.
ACS Chem Neurosci ; 9(6): 1327-1337, 2018 06 20.
Article de Anglais | MEDLINE | ID: mdl-29597343

RÉSUMÉ

Psychostimulant reinforcement is mediated by stimulation of both dopamine (DA) D1-like and D2-like receptors, suggesting that pharmacotherapy agents with a dual DA receptor mechanism may be useful for managing psychostimulant abuse. (-)-Stepholidine (L-SPD) is a Chinese herbal extract that functions as a D1-like receptor agonist and D2-like receptor antagonist. L-SPD has been shown to attenuate the reinforcing effects of heroin; however, its effects on the synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV) have not been examined. The current study determined the effects of L-SPD on reinstatement of MDPV-seeking behavior in the drug intravenous self-administration (IVSA) and conditioned place preference (CPP) paradigms. To determine whether the effects of L-SPD were specific to psychostimulant reinforcement, we also examined its effects on sucrose-seeking behavior. Using a locomotor activity assay, we tested the locomotor effects of L-SPD, as well as its effects on MDPV-induced hyperactivity. The results of a battery of in vitro binding and functional assays confirmed that L-SPD functioned as a D1-like receptor agonist and D2-like receptor antagonist. In behavioral experiments, L-SPD dose-dependently attenuated cue plus MDPV-primed reinstatement of MDPV-seeking behavior in the IVSA model. The highest dose of L-SPD also attenuated MDPV-primed reinstatement of MDPV CPP, as well as cue-induced reinstatement of sucrose-seeking. L-SPD had no significant locomotor effects, and did not modulate the robust hyperactivity induced by MDPV. The current findings show for the first time a robust reinstatement effect with MDPV, which can be reduced by L-SPD. These results establish a role for DA receptors in drug-seeking behavior for MDPV.


Sujet(s)
Berbérine/analogues et dérivés , Agonistes de la dopamine/pharmacologie , Antagonistes de la dopamine/pharmacologie , Comportement de recherche de substances/effets des médicaments et des substances chimiques , Animaux , Comportement animal/effets des médicaments et des substances chimiques , Benzodioxoles/pharmacologie , Berbérine/pharmacologie , Cocaïne/pharmacologie , Extinction (psychologie)/effets des médicaments et des substances chimiques , Humains , Pyrrolidines/pharmacologie , Rat Sprague-Dawley , Récepteur dopamine D1/agonistes , Récepteur dopamine D1/effets des médicaments et des substances chimiques , Cathinone de synthèse
5.
Drug Alcohol Depend ; 186: 75-79, 2018 05 01.
Article de Anglais | MEDLINE | ID: mdl-29550625

RÉSUMÉ

BACKGROUND AND PURPOSE: Little is known about how chemokine systems influence the behavioral effects of designer cathinones and psychostimulants. The chemokine CXCL12 and its principal receptor target, CXCR4, are of particular interest because CXCR4 activation enhances mesolimbic dopamine output that facilitates psychostimulant reward, reinforcement, and locomotor activation. Repeated cocaine enhances CXCL12 gene expression in the midbrain and produces conditioned place preference (CPP) that is inhibited by a CXCR4 antagonist. Yet, interactions between chemokines and synthetic cathinones remain elusive. METHODS: We tested the hypothesis that an FDA-approved CXCR4 antagonist (AMD3100) inhibits MDPV-induced reward, locomotor activation and positive affective state in rats using a triad of behavioral assays (CPP, open field, and 50-kHz ultrasonic vocalizations [USVs]). KEY RESULTS: AMD3100 (1, 2.5, 5, 10 mg/kg, ip) significantly reduced MDPV (2 mg/kg, ip)-evoked hyper-locomotion in a dose-related manner. AMD3100 (1, 5, 10 mg/kg) administered during CPP conditioning caused a significant, dose-dependent reduction of MDPV (2 mg/kg x 4 days) place preference. MDPV injection elicited significantly greater 50 kHz USVs in vehicle-pretreated rats but not in AMD3100-pretreated rats. CONCLUSION AND IMPLICATION: A CXCR4 antagonist reduced the rewarding and locomotor-activating effects of MDPV. Our results identify the existence of chemokine/cathinone interactions and suggest the rewarding and stimulant effects of MDPV, similar to cocaine, require an active CXCL12/CXCR4 system.


Sujet(s)
Alcaloïdes/antagonistes et inhibiteurs , Stimulants du système nerveux central/antagonistes et inhibiteurs , Chimiokines/pharmacologie , Drogues fabriquées clandestinement/pharmacologie , Activité motrice/effets des médicaments et des substances chimiques , Récepteurs CXCR4/antagonistes et inhibiteurs , Récompense , Alcaloïdes/pharmacologie , Animaux , Benzylamines , Stimulants du système nerveux central/pharmacologie , Conditionnement opérant/effets des médicaments et des substances chimiques , Cyclames , Relation dose-effet des médicaments , Composés hétérocycliques/pharmacologie , Mâle , Rats , Rat Sprague-Dawley , Vocalisation animale/effets des médicaments et des substances chimiques
6.
Psychopharmacology (Berl) ; 234(11): 1671-1681, 2017 Jun.
Article de Anglais | MEDLINE | ID: mdl-28251297

RÉSUMÉ

RATIONALE: Metabotropic glutamate 2 and 3 (mGluR2/3) receptors are implicated in drug addiction as they limit excessive glutamate release during relapse. N-acetylaspartylglutamate (NAAG) is an endogenous mGluR2/3 agonist that is inactivated by the glutamate carboxypeptidase II (GCPII) enzyme. GCPII inhibitors, and NAAG itself, attenuate cocaine-seeking behaviors. However, their effects on the synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV) have not been examined. OBJECTIVES: We determined whether withdrawal following repeated MDPV administration alters GCPII expression in corticolimbic regions. We also examined whether a GCPII inhibitor (2-(phosphonomethyl)-pentanedioic acid (2-PMPA)), and NAAG, reduce the rewarding and locomotor-stimulant effects of MDPV in rats. METHODS: GCPII was assessed following repeated MDPV exposure (7 days). The effects of 2-PMPA and NAAG on acute MDPV-induced hyperactivity were determined using a locomotor test. We also examined the inhibitory effects of 2-PMPA and NAAG on MDPV-induced place preference, and whether the mGluR2/3 antagonist LY341495 could prevent these effects. RESULTS: MDPV withdrawal reduced GCPII expression in the prefrontal cortex. Systemic injection of 2-PMPA (100 mg/kg) did not affect the hyperactivity produced by MDPV (0.5-3 mg/kg). However, nasal administration of NAAG did reduce MDPV-induced ambulation, but only at the highest dose (500 µg/10 µl). We also showed that 2-PMPA (10-30 mg/kg) and NAAG (10-500 µg/10 µl) dose-dependently attenuated MDPV place preference, and that the effect of NAAG was blocked by LY341495 (3 mg/kg). CONCLUSIONS: These findings demonstrate that MDPV withdrawal produces dysregulation in the endogenous NAAG-GCPII signaling pathway in corticolimbic circuitry. Systemic administration of the GCPII inhibitor 2-PMPA, or NAAG, attenuates MDPV reward.


Sujet(s)
Alcaloïdes/administration et posologie , Benzodioxoles/administration et posologie , Dipeptides/pharmacologie , Glutamate carboxypeptidase II/biosynthèse , Composés organiques du phosphore/pharmacologie , Pyrrolidines/administration et posologie , Récompense , Acides aminés/pharmacologie , Animaux , Conditionnement psychologique/effets des médicaments et des substances chimiques , Conditionnement psychologique/physiologie , Relation dose-effet des médicaments , Antagonistes des acides aminés excitateurs/pharmacologie , Glutamate carboxypeptidase II/antagonistes et inhibiteurs , Mâle , Rats , Rat Sprague-Dawley , Récepteurs métabotropes au glutamate/antagonistes et inhibiteurs , Récepteurs métabotropes au glutamate/physiologie , Xanthènes/pharmacologie , Cathinone de synthèse
7.
ACS Comb Sci ; 18(8): 461-74, 2016 08 08.
Article de Anglais | MEDLINE | ID: mdl-27314875

RÉSUMÉ

Botulism is caused by potent and specific bacterial neurotoxins that infect host neurons and block neurotransmitter release. Treatment for botulism is limited to administration of an antitoxin within a short time window, before the toxin enters neurons. Alternatively, current botulism drug development targets the toxin light chain, which is a zinc-dependent metalloprotease that is delivered into neurons and mediates long-term pathology. Several groups have identified inhibitory small molecules, peptides, or aptamers, although no molecule has advanced to the clinic due to a lack of efficacy in advanced models. Here we used a homogeneous high-throughput enzyme assay to screen three libraries of drug-like small molecules for new chemotypes that modulate recombinant botulinum neurotoxin light chain activity. High-throughput screening of 97088 compounds identified numerous small molecules that activate or inhibit metalloprotease activity. We describe four major classes of inhibitory compounds identified, detail their structure-activity relationships, and assess their relative inhibitory potency. A previously unreported chemotype in any context of enzyme inhibition is described with potent submicromolar inhibition (Ki = 200-300 nM). Additional detailed kinetic analyses and cellular cytotoxicity assays indicate the best compound from this series is a competitive inhibitor with cytotoxicity values around 4-5 µM. Given the potency and drug-like character of these lead compounds, further studies, including cellular activity assays and DMPK analysis, are justified.


Sujet(s)
Toxines botuliniques/antagonistes et inhibiteurs , Inhibiteurs de protéases/composition chimique , Bibliothèques de petites molécules/composition chimique , Animaux , Lignée cellulaire tumorale , Survie cellulaire/effets des médicaments et des substances chimiques , Tests de criblage à haut débit , Humains , Cinétique , Souris , Inhibiteurs de protéases/pharmacologie , Inhibiteurs de protéases/toxicité , Pyrazoles/composition chimique , Pyridines/composition chimique , Quinoléines/composition chimique , Relation structure-activité , Thiadiazoles/composition chimique
8.
Neuropharmacology ; 108: 111-9, 2016 09.
Article de Anglais | MEDLINE | ID: mdl-27085607

RÉSUMÉ

Synthetic cathinones produce dysregulation of monoamine systems, but their effects on the glutamate system and the influence of glutamate on behavioral effects related to cathinone abuse are unknown. A principal regulator of glutamate homeostasis is glutamate transporter subtype 1 (GLT-1), an astrocytic protein that clears glutamate from the extracellular space and influences behavioral effects of established psychostimulants. We hypothesized that repeated administration of the synthetic cathinone, MDPV (3,4-methylenedioxypyrovalerone), would affect GLT-1 expression in the corticolimbic circuit, and that a GLT-1 activator (ceftriaxone, CTX) would reduce rewarding and locomotor-stimulant effects of MDPV in rats. GLT-1 protein expression in the nucleus accumbens (NAcc), but not prefrontal cortex (PFC), was decreased following withdrawal (2, 5 and 10 days) from repeated MDPV treatment, but not immediately after the last MDPV injection. CTX (200 mg/kg) pretreatment did not affect acute locomotor activation produced by MDPV (0.5, 1, 3 mg/kg). However, CTX (200 mg/kg) administered during a 7-day MDPV treatment paradigm attenuated the development of MDPV-induced sensitization of repetitive movements in rats challenged with MDPV following 11 days of drug abstinence. Pretreatment with CTX (200 mg/kg) during a 4-day MDPV (2 mg/kg) conditioned place preference (CPP) paradigm reduced the development of place preference produced by MDPV. The present data demonstrate dysregulation of corticolimbic glutamate transport systems during withdrawal from chronic MDPV exposure, and show that a GLT-1 transporter activator disrupts behavioral effects of MDPV that are related to synthetic cathinone abuse.


Sujet(s)
Alcaloïdes/pharmacologie , Benzodioxoles/pharmacologie , Transporteur-2 d'acides aminés excitateurs/antagonistes et inhibiteurs , Transporteur-2 d'acides aminés excitateurs/métabolisme , Locomotion/effets des médicaments et des substances chimiques , Pyrrolidines/pharmacologie , Récompense , Animaux , Ceftriaxone/pharmacologie , Relation dose-effet des médicaments , Transporteur-2 d'acides aminés excitateurs/agonistes , Locomotion/physiologie , Mâle , Rats , Cathinone de synthèse
9.
Carbohydr Res ; 409: 63-8, 2015 May 29.
Article de Anglais | MEDLINE | ID: mdl-25957213

RÉSUMÉ

Lemonose is a component of the antibiotic lemonomycin and other antibiotics and natural products. Three routes to the synthesis of the title compound, a protected, desmethyl derivative of lemonose, from l-rhamnose or its glycal, were investigated based on electrophilic cyclization, epoxidation-ring opening, and deoxygenation of an intermediate that was used in the synthesis of the amino sugar callipeltose. The deoxygenation route was successful and it provided the title compound, which was then converted to a phenyl thioglycoside.


Sujet(s)
Hétérosides/composition chimique , Hétérosides/synthèse chimique , Thioglycosides/composition chimique , Séquence glucidique
10.
ACS Chem Biol ; 10(4): 1099-109, 2015 Apr 17.
Article de Anglais | MEDLINE | ID: mdl-25588114

RÉSUMÉ

We previously discovered that one specific scalemic preparation of myricanol (1), a constituent of Myrica cerifera (bayberry/southern wax myrtle) root bark, could lower the levels of the microtubule-associated protein tau (MAPT). The significance is that tau accumulates in a number of neurodegenerative diseases, the most common being Alzheimer's disease (AD). Herein, a new synthetic route to prepare myricanol using a suitable boronic acid pinacol ester intermediate is reported. An X-ray crystal structure of the isolated myricanol (1) was obtained and showed a co-crystal consisting of (+)-aR,11S-myricanol (2) and (-)-aS,11R-myricanol (3) coformers. Surprisingly, 3, obtained from chiral separation from 1, reduced tau levels in both cultured cells and ex vivo brain slices from a mouse model of tauopathy at reasonable mid-to-low micromolar potency, whereas 2 did not. SILAC proteomics and cell assays revealed that 3 promoted tau degradation through an autophagic mechanism, which was in contrast to that of other tau-lowering compounds previously identified by our group. During the course of structure-activity relationship (SAR) development, we prepared compound 13 by acid-catalyzed dehydration of 1. 13 had undergone an unexpected structural rearrangement through the isomyricanol substitution pattern (e.g., 16), as verified by X-ray structural analysis. Compound 13 displayed robust tau-lowering activity, and, importantly, its enantiomers reduced tau levels similarly. Therefore, the semisynthetic analogue 13 provides a foundation for further development as a tau-lowering agent without its SAR being based on chirality.


Sujet(s)
Diarylheptanoïdes/composition chimique , Bibliothèques de petites molécules/pharmacologie , Protéines tau/métabolisme , Animaux , Autophagie , Encéphale/effets des médicaments et des substances chimiques , Encéphale/métabolisme , Techniques de chimie synthétique , Diarylheptanoïdes/isolement et purification , Diarylheptanoïdes/pharmacologie , Épitopes/métabolisme , Cellules HEK293/effets des médicaments et des substances chimiques , Humains , Mâle , Souris transgéniques , Structure moléculaire , Thérapie moléculaire ciblée , Bibliothèques de petites molécules/synthèse chimique , Bibliothèques de petites molécules/composition chimique , Stéréoisomérie , Tauopathies/traitement médicamenteux , Tauopathies/génétique , Tauopathies/métabolisme , Protéines tau/génétique , Protéines tau/immunologie
11.
Br J Pharmacol ; 172(3): 883-94, 2015 Feb.
Article de Anglais | MEDLINE | ID: mdl-25255824

RÉSUMÉ

BACKGROUND AND PURPOSE: Synthetic cathinones, commonly referred to as 'bath salts', are a group of amphetamine-like drugs gaining popularity worldwide. 4-Methylmethcathinone (mephedrone, MEPH) is the most commonly abused synthetic cathinone in the UK, and exerts its effects by acting as a substrate-type releaser at monoamine transporters. Similar to other cathinone-related compounds, MEPH has a chiral centre and exists stably as two enantiomers: R-mephedrone (R-MEPH) and S-mephedrone (S-MEPH). EXPERIMENTAL APPROACH: Here, we provide the first investigation into the neurochemical and behavioural effects of R-MEPH and S-MEPH. We analysed both enantiomers in rat brain synaptosome neurotransmitter release assays and also investigated their effects on locomotor activity (e.g. ambulatory activity and repetitive movements), behavioural sensitization and reward. KEY RESULTS: Both enantiomers displayed similar potency as substrates (i.e. releasers) at dopamine transporters, but R-MEPH was much less potent than S-MEPH as a substrate at 5-HT transporters. Locomotor activity was evaluated in acute and repeated administration paradigms, with R-MEPH producing greater repetitive movements than S-MEPH across multiple doses. After repeated drug exposure, only R-MEPH produced sensitization of repetitive movements. R-MEPH produced a conditioned place preference whereas S-MEPH did not. Lastly, R-MEPH and S-MEPH produced biphasic profiles in an assay of intracranial self-stimulation (ICSS), but R-MEPH produced greater ICSS facilitation than S-MEPH. CONCLUSIONS AND IMPLICATIONS: Our data are the first to demonstrate stereospecific effects of MEPH enantiomers and suggest that the predominant dopaminergic actions of R-MEPH (i.e. the lack of serotonergic actions) render this stereoisomer more stimulant-like when compared with S-MEPH. This hypothesis warrants further study.


Sujet(s)
Comportement animal/effets des médicaments et des substances chimiques , Encéphale/effets des médicaments et des substances chimiques , Métamfétamine/analogues et dérivés , Activité motrice/effets des médicaments et des substances chimiques , Animaux , Encéphale/métabolisme , Mâle , Métamfétamine/composition chimique , Métamfétamine/pharmacologie , Agents neuromédiateurs/métabolisme , Rats , Rat Sprague-Dawley , Stéréoisomérie , Relation structure-activité
12.
Neuropharmacology ; 91: 109-16, 2015 Apr.
Article de Anglais | MEDLINE | ID: mdl-25496724

RÉSUMÉ

Knowledge about the neuropharmacology of mephedrone (MEPH) applies primarily to the racemate, or street form of the drug, but not to its individual enantiomers. Here, through chemical isolation of MEPH enantiomers and subsequent behavioral characterization in established invertebrate (planarian) assays, we began separating adverse effects of MEPH from potential therapeutic actions. We first compared stereotypical and environmental place conditioning (EPC) effects of racemic MEPH, S-MEPH, and R-MEPH. Stereotypy was enhanced by acute treatment (100-1000 µM) with each compound; however, S-MEPH was less potent and efficacious than racemate and R-MEPH. Both R-MEPH (10, 100, 250 µM) and racemate (100 µM) produced EPC, but S-MEPH was ineffective at all concentrations (10-100 µM). After showing that S-MEPH lacked rewarding efficacy, we investigated its ability to alter three of cocaine's behavioral effects (EPC, withdrawal, and stereotypy). Cocaine (1 µM) produced EPC that was abolished when S-MEPH (100 µM) was administered after cocaine conditioning. Spontaneous withdrawal from chronic cocaine exposure caused a reduction in motility that was not evident during acute or continuous cocaine treatment but was attenuated by S-MEPH (100 µM) treatment during the cocaine abstinence interval. Acute stereotypy produced by 1 mM cocaine, nicotine or racemic MEPH was not affected by S-MEPH (10-250 µM). The present results obtained using planarian assays suggest that the R-enantiomer of MEPH is predominantly responsible for its stimulant and rewarding effects and the S-enantiomer is capable of antagonizing cocaine's addictive-like behaviors without producing rewarding effects of its own.


Sujet(s)
Cocaïne/pharmacologie , Conditionnement psychologique/effets des médicaments et des substances chimiques , Métamfétamine/analogues et dérivés , Mouvement/effets des médicaments et des substances chimiques , Animaux , Métamfétamine/composition chimique , Métamfétamine/pharmacologie , Planaires , Récompense , Comportement stéréotypé/effets des médicaments et des substances chimiques , Syndrome de sevrage
14.
Curr Top Med Chem ; 14(18): 2094-102, 2014.
Article de Anglais | MEDLINE | ID: mdl-25335884

RÉSUMÉ

We describe here the state of the art of certain aspects concerning potential small molecule therapy directed toward botulism, by inhibition of the zinc-protease containing light chain (LC) of botulinum neurotoxin BoNT/A from the anaerobic bacillus Clostridium botulinum. Botulinum neurotoxins (BoNTs) are comprised of eight serologically-distinct proteins (A - H), several of which are further divided, such as BoNT/A which has five subtypes. The BoNTs are the most toxic substances known to mankind, causing a form of flaccid paralysis that can be rapid and is often lethal. BoNT/A is comprised of a ~100 kDa heavy chain (HC) attached via a single disulfide Cys-Cys bond to a ~50 kDa LC. The HC mediates transport to and uptake by presynaptic glutamatergic neurons, where the LC cleaves the protein SNAP-25 and thus prevents vesicular trafficking and release of acetylcholine. The Zn-endoprotease activity of the LC of BoNT/A is a target for the development of small molecule inhibitors of BoNT/A-mediated toxicity. A variety of BoNT/A LC inhibitors have been described to date and we focus here primarily on the Zn-binding 8-hydroxyquinoline structural type as well as some of the previously-described hydroxamic acids.


Sujet(s)
Antidotes/pharmacologie , Toxines botuliniques de type A/antagonistes et inhibiteurs , Chélateurs/pharmacologie , Antienzymes/pharmacologie , Acides hydroxamiques/pharmacologie , Hydroxy-8 quinoléine/pharmacologie , Animaux , Antidotes/composition chimique , Toxines botuliniques de type A/composition chimique , Toxines botuliniques de type A/toxicité , Botulisme/traitement médicamenteux , Botulisme/anatomopathologie , Chélateurs/composition chimique , Clostridium botulinum/pathogénicité , Clostridium botulinum/physiologie , Antienzymes/composition chimique , Humains , Acides hydroxamiques/composition chimique , Modèles moléculaires , Motoneurones/effets des médicaments et des substances chimiques , Motoneurones/anatomopathologie , Hydroxy-8 quinoléine/composition chimique , Paralysie/traitement médicamenteux , Paralysie/anatomopathologie , Bibliothèques de petites molécules/composition chimique , Bibliothèques de petites molécules/pharmacologie , Transmission synaptique/effets des médicaments et des substances chimiques , Zinc/composition chimique , Zinc/métabolisme
15.
J Med Chem ; 57(3): 669-76, 2014 Feb 13.
Article de Anglais | MEDLINE | ID: mdl-24387280

RÉSUMÉ

Botulinum neurotoxins (BoNT) are the most potent toxins known and a significant bioterrorist threat. Few small molecule compounds have been identified that are active in cell-based or animal models, potentially due to toxin enzyme plasticity. Here we screened commercially available quinolinols, as well as synthesized hydroxyquinolines. Seventy-two compounds had IC50 values below 10 µM, with the best compound exhibiting submicromolar inhibition (IC50 = 0.8 µM). Structure-activity relationship trends showed that the enzyme tolerates various substitutions at R1 but has a clear preference for bulky aryl amide groups at R2, while methylation at R3 increased inhibitor potency. Evaluation of the most potent compounds in an ADME panel showed that these compounds possess poor solubility at pH 6.8, but display excellent solubility at low pH, suggesting that oral dosing may be possible. Our data show the potential of quinolinol compounds as BoNT therapeutics due to their good in vitro potencies and favorable ADME properties.


Sujet(s)
Toxines botuliniques de type A/antagonistes et inhibiteurs , Hydroxyquinoléines/composition chimique , Animaux , Domaine catalytique , Humains , Concentration en ions d'hydrogène , Hydroxyquinoléines/synthèse chimique , Hydroxyquinoléines/pharmacologie , Techniques in vitro , Microsomes du foie/métabolisme , Rats , Rat Sprague-Dawley , Solubilité , Relation structure-activité
16.
Bioorg Med Chem Lett ; 24(4): 1116-21, 2014 Feb 15.
Article de Anglais | MEDLINE | ID: mdl-24461299

RÉSUMÉ

We designed a series of anilino-indoylmaleimides based on structural elements from literature JAK3 inhibitors 3 and 4, and our lead 5. These new compounds were tested as inhibitors of JAKs 1, 2 and 3 and TYK2 for therapeutic intervention in rheumatoid arthritis (RA). Our requirements, based on current scientific rationale for optimum efficacy against RA with reduced side effects, was for potent, mixed JAK1 and 3 inhibition, and selectivity over JAK2. Our efforts yielded a potent JAK3 inhibitor 11d and its eutomer 11e. These compounds were highly selective for inhibition of JAK3 over JAK2 and TYK. The compounds displayed only modest JAK1 inhibition.


Sujet(s)
Dérivés de l'aniline/pharmacologie , Janus kinase 3/antagonistes et inhibiteurs , Maléimides/pharmacologie , Inhibiteurs de protéines kinases/pharmacologie , Dérivés de l'aniline/synthèse chimique , Dérivés de l'aniline/composition chimique , Relation dose-effet des médicaments , Humains , Janus kinase 3/métabolisme , Maléimides/synthèse chimique , Maléimides/composition chimique , Modèles moléculaires , Structure moléculaire , Inhibiteurs de protéines kinases/synthèse chimique , Inhibiteurs de protéines kinases/composition chimique , Relation structure-activité
17.
J Mol Neurosci ; 52(3): 446-58, 2014 Mar.
Article de Anglais | MEDLINE | ID: mdl-24277343

RÉSUMÉ

Severe seizure activity is associated with reoccurring cycles of excitotoxicity and oxidative stress that result in progressive neuronal damage and death. Intervention with these pathological processes is a compelling disease-modifying strategy for the treatment of seizure disorders. We have optimized a series of small molecules for neuroprotective and anticonvulsant activity as well as altered their physical properties to address potential metabolic liabilities, to improve CNS penetration, and to prolong the duration of action in vivo. Utilizing phenotypic screening of hippocampal cultures with nutrient medium depleted of antioxidants as a disease model, cell death and decreased neuronal viability produced by acute treatment with glutamate or hydrogen peroxide were prevented. Modifications to our previously reported proof of concept compounds have resulted in a lead which has full neuroprotective action at <1 nM and antiseizure activity across six animal models including the kindled rat and displays excellent pharmacokinetics including high exposure to the brain. These modifications have also eliminated the requirement for a chiral molecule, removing the possibility of racemization and making large-scale synthesis more easily accessible. These studies strengthen our earlier findings which indicate that potent, multifunctional neuroprotective anticonvulsants are feasible within a single molecular entity which also possesses favorable CNS-active drug properties in vitro and in vivo.


Sujet(s)
Anticonvulsivants/synthèse chimique , Neurones/effets des médicaments et des substances chimiques , Neuroprotecteurs/synthèse chimique , Animaux , Anticonvulsivants/effets indésirables , Anticonvulsivants/pharmacocinétique , Anticonvulsivants/pharmacologie , Cellules Caco-2 , Cellules cultivées , Entérocytes/effets des médicaments et des substances chimiques , Humains , Souris , Souris de lignée C57BL , Neuroprotecteurs/effets indésirables , Neuroprotecteurs/pharmacocinétique , Neuroprotecteurs/pharmacologie , Rats , Rat Sprague-Dawley
18.
Bioorg Med Chem ; 20(18): 5642-8, 2012 Sep 15.
Article de Anglais | MEDLINE | ID: mdl-22892214

RÉSUMÉ

Riluzole (1) is an approved therapeutic for the treatment of ALS and has also demonstrated anti-melanoma activity in metabotropic glutamate GRM1 positive cell lines, a mouse xenograft assay and human clinical trials. Highly variable drug exposure following oral administration among patients, likely due to variable first pass effects from heterogeneous CYP1A2 expression, hinders its clinical use. In an effort to mitigate effects of this clearance pathway and uniformly administer riluzole at efficacious exposure levels, several classes of prodrugs of riluzole were designed, synthesized, and evaluated in multiple in vitro stability assays to predict in vivo drug levels. The optimal prodrug would possess the following profile: stability while transiting the digestive system, stability towards first pass metabolism, and metabolic lability in the plasma releasing riluzole. (S)-O-Benzyl serine derivative 9 was identified as the most promising therapeutically acceptable prodrug.


Sujet(s)
Sclérose latérale amyotrophique/traitement médicamenteux , Conception de médicament , Mélanome/traitement médicamenteux , Promédicaments/synthèse chimique , Promédicaments/pharmacologie , Riluzole/métabolisme , Riluzole/pharmacologie , Sclérose latérale amyotrophique/métabolisme , Animaux , Cytochrome P-450 CYP1A2/biosynthèse , Cytochrome P-450 CYP1A2/métabolisme , Stabilité de médicament , Humains , Mélanome/métabolisme , Souris , Microsomes du foie/métabolisme , Structure moléculaire , Promédicaments/composition chimique , Promédicaments/métabolisme , Riluzole/sang , Riluzole/synthèse chimique
19.
Bioorg Med Chem Lett ; 22(11): 3754-7, 2012 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-22542019

RÉSUMÉ

Botulinum neurotoxins (BoNTs) are the most toxic proteins known to man, exposure to which results in flaccid paralysis. Given their extreme potency, these proteins have become studied as possible weapons of bioterrorism; however, effective treatments that function after intoxication have not progressed to the clinic. Here, we have reexamined one of the most effective inhibitors, 2,4-dichlorocinnamyl hydroxamate, in the context of the known plasticity of the BoNT/A light chain metalloprotease. Our studies have shown that modifications of this compound are tolerated and result in improved inhibitors, with the best compound having an IC(50) of 0.23 µM. Given the inconsistency of structure-activity relationship trends observed across similar compounds, this data argues for caution in extrapolating across structural series.


Sujet(s)
Toxines botuliniques de type A/antagonistes et inhibiteurs , Acides hydroxamiques/composition chimique , Inhibiteurs de protéases/composition chimique , Sites de fixation , Toxines botuliniques de type A/métabolisme , Simulation numérique , Structure tertiaire des protéines , Relation structure-activité
20.
J Mol Neurosci ; 47(2): 368-79, 2012 Jun.
Article de Anglais | MEDLINE | ID: mdl-22535312

RÉSUMÉ

Severe seizure activity is associated with recurring cycles of excitotoxicity and oxidative stress that result in progressive neuronal damage and death. Intervention to halt these pathological processes is a compelling disease-modifying strategy for the treatment of seizure disorders. In the present study, a core small molecule with anticonvulsant activity has been structurally optimized for neuroprotection. Phenotypic screening of rat hippocampal cultures with nutrient medium depleted of antioxidants was utilized as a disease model. Increased cell death and decreased neuronal viability produced by acute treatment with glutamate or hydrogen peroxide were prevented by our novel molecules. The neuroprotection associated with this chemical series has marked structure activity relationships that focus on modification of the benzylic position of a 2-phenyl-2-hydroxyethyl sulfamide core structure. Complete separation between anticonvulsant activity and neuroprotective action was dependent on substitution at the benzylic carbon. Chiral selectivity was evident in that the S-enantiomer of the benzylic hydroxy group had neither neuroprotective nor anticonvulsant activity, while the R-enantiomer of the lead compound had full neuroprotective action at <40 nM and antiseizure activity in three animal models. These studies indicate that potent, multifunctional neuroprotective anticonvulsants are feasible within a single molecular entity.


Sujet(s)
Anticonvulsivants/pharmacologie , Épilepsie/traitement médicamenteux , Neurones/effets des médicaments et des substances chimiques , Neuroprotecteurs/pharmacologie , Sulfonamides/pharmacologie , Animaux , Anticonvulsivants/composition chimique , Cellules Caco-2 , Cellules cultivées , Modèles animaux de maladie humaine , Épilepsie/anatomopathologie , Hippocampe/cytologie , Hippocampe/effets des médicaments et des substances chimiques , Humains , Souris , Neurones/anatomopathologie , Neuroprotecteurs/composition chimique , Rats , Sulfonamides/composition chimique
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